A UK wholesaler shopping for inventory software meets the most metered pricing in small-business SaaS. Unleashed lists Core at £269 per month for 3 users with a 100 sales orders per month cap, then £49 to £59 per additional user, order-volume upgrades at £50 to £350 per month, and add-ons from £29 to £351 per month (all verified on Unleashed's UK pricing page, July 2026). Cin7 Core lists at $349, $599 and $999 per month with user and order caps (the vendor prices in dollars). Linnworks is quote-only, reported around £150 a month for 1,000 orders and then £0.14 per order; Sage 200 is reported around £331 to £374 per month plus per-user. Your stock data ends up in silos, and the analytics to see across them is a paid tier.
What metered inventory SaaS costs at 5 users and 500 orders
| Capability | Metered inventory SaaS | On Node (flat, hourly billed) |
|---|---|---|
| Stock, multi-warehouse, purchasing & orders | Unleashed Core: £269/mo (3 users, 100 orders/mo cap) | ERPNext (Large): £75, unlimited orders and users |
| Users 4 and 5 | +2 x £49 = £98/mo | £0: no user meter |
| Order volume to ~500/mo | Upgrade: £50/mo (rising to £350 at higher bands) | £0: no order meter |
| Analytics & reporting | Add-on tiers: £29-351/mo | Metabase (Small): £21 |
| Courier & marketplace integrations | Per-connector add-ons or per-order fees | n8n (Medium): £45 |
| Trade-customer support desk | Per-agent helpdesk SaaS | Zammad (Medium): £45 |
| Identity, SSO & audit | Spread across the above | Included with your apps: £0 |
| Indicative total | £417/mo before analytics, rising with orders | £186 flat: no user, order or SKU meters |
The Node column is a sum of app rates and nothing else: no platform fee, no seat count, and the headline is the meter that is not there: no per-order fees. Double your order volume and the left column climbs through upgrade bands; the right column does not move. These are list and reported prices; ask for a like-for-like figure for your operation.
What your warehouse runs on Node
n8n deploys self-serve, in minutes, from the signup portal (as do Nextcloud, EspoCRM and DocuSeal); ERPNext and the rest are managed setup, deployed and connected by our engineers.
Stock & orders: ERPNext (managed setup) (Large, £75/month equivalent): stock across multiple warehouses, purchasing, batch and serial tracking, sales orders and accounting in one open source system with no order, user or SKU caps. Distribution is one of Frappe's own published verticals, and its case studies include Apna Mart at 200+ stores and 60,000 products.
Analytics: Metabase (managed setup) (Small, £21): margin by customer, stock turn by SKU, dead stock reports, straight off your own ERPNext database. This is the capability the inventory SaaS vendors package as an add-on tier.
Integrations: n8n (self-serve) (Medium, £45): courier bookings, marketplace order pulls, stock-level alerts and reorder triggers, built once and run flat-rate instead of paying per connector or per order.
Trade-customer support: Zammad (managed setup) (Medium, £45): a shared inbox for order queries, returns and account questions with full history per trade customer. Zammad's published references include appliance maker De'Longhi.
B2B ordering & invoicing: WordPress with WooCommerce or NocoDB (managed setup) as a trade ordering front-end feeding ERPNext, and Invoice Ninja (Small, £22) if you want standalone invoicing before the full ERP lands. Something bespoke already in the mix? Bring Your Own App hosts it alongside.
Your stock data, your software, your exit
The compliance story here is lighter than in regulated sectors, so we will lead with the commercial one: ownership and single-supplier risk. Linnworks' price rises produced an entire cottage industry of "Linnworks alternative" threads because the data and workflows were locked in. On Node, ERPNext is open source, your data sits in a standard database inside a network-isolated tenant on hardware we own in UK data centres, behind your own single sign-on realm, and a UK GDPR Article 28 DPA is standard. One honest caveat repeated from the FAQ: ERPNext is an implementation project, not a toggle. We host and manage the platform; the ERP configuration is real work, yours or a partner's, and we scope it before you commit.
AI on operational data, without it leaving the UK
Drafting supplier chasers, summarising slow-mover reports, first-pass answers to trade-customer emails: useful AI work on commercially sensitive data. The AI gateway labels every model UK-hosted or partner-routed; UK-hosted models run on GPUs we own, so prompt content never leaves our infrastructure. Metered per token in GBP on the same hourly invoice: see the model catalogue.
Start with the glue, or scope the ERP
Deploy n8n or Nextcloud yourself in minutes with £25 of free credit, or tell an engineer your order volumes and warehouse layout and we will scope the ERPNext implementation.
Frequently asked questions
Is there really no per-order or per-user charge?
None, anywhere. The bill is a sum of app rates from the published rate card: ERPNext is priced by the resources it runs on, not by orders processed, users logged in or SKUs held. Ship 100 orders or 10,000 in a month and the software line does not move, which is precisely the meter Unleashed and Linnworks turn as you grow.
How does the billing work?
Everything is billed hourly against a published rate card with no minimum term and no contract; the monthly figures on this page are equivalents for comparison. Stop an app and the meter stops. There is no renewal negotiation and no tier jump waiting at order 101.
Is ERPNext honestly a match for Unleashed or Cin7?
On stock control, yes and more: multi-warehouse, batch and serial tracking, purchasing, sales orders and accounting in one system, where the inventory SaaS tools stop at inventory. Where we will be straight with you: ERPNext is an implementation project, not a toggle. Item, warehouse and pricing discipline is real work, done by you or a partner, and we scope it before you commit.
Do you integrate with Royal Mail, DPD and the marketplaces?
Not natively, and we will say so rather than let you assume. ERPNext has no out-of-the-box UK courier or marketplace connectors the way Linnworks does. Integrations are built with n8n and the API: courier label calls, marketplace order pulls, stock-level pushes. That is genuine setup work, but once built it runs on a flat-rate app with no per-order clip.
Who actually runs ERPNext at scale?
Frappe, its maker, reports 30,000+ companies using ERPNext; treat that as a vendor figure. Its published case studies include Apna Mart, running 200+ stores and 60,000 products on it, alongside warehouse operators. Other companies using ERPNext include Zerodha, India's largest stockbroker. It is not exotic software; it is just not rented by the order.
What is the single-supplier risk if we move?
Lower than where you are, which is the quiet argument for open source. Linnworks' price rises spawned a cottage industry of alternatives threads because customers were locked in. ERPNext is open source and your data sits in a standard database in your own tenant: leave us and you can take the software, the schema and the data with you. Try asking that of an inventory SaaS.