The verdict in three sentences
In an SMB of 100 to 500 employees in London or Amsterdam, time lost searching for a procedure, product sheet or contract clause reaches 2 to 4 hours per week per employee. Microsoft 365 Copilot, at about EUR 28 per user per month, is a good option if all your documentation lives in SharePoint and every employee will use it. A custom RAG assistant at EUR 20,000-45,000 (about USD 22,000-49,000), plus EUR 200 to 1,500 of monthly usage, becomes more cost-effective from 150 users or as soon as answers must also come from the ERP, with access rights enforced and sources cited.
Copilot, ChatGPT Enterprise or a custom RAG assistant
RAG (retrieval-augmented generation) makes a language model answer only from your documents, citing the passages used. The three options follow different cost logics.
| Criterion | Microsoft 365 Copilot | ChatGPT Enterprise or equivalent | Custom RAG assistant |
|---|---|---|---|
| Upfront cost | EUR 0 to 5,000 (SharePoint preparation) | EUR 0 to 5,000 | EUR 20,000 to 45,000 |
| Monthly cost for 250 users | About EUR 7,000 | EUR 6,000 to 9,000 | EUR 200 to 1,500 usage, plus EUR 300 to 600 maintenance |
| 3-year cost (250 users) | About EUR 252,000 | EUR 216,000 to 324,000 | EUR 38,000 to 120,000 |
| Connected sources | Microsoft 365 | Uploaded files, some connectors | SharePoint, ERP, DMS, intranet, tickets |
| Access rights enforced | Yes, inherited from Microsoft 365 | Partial | Yes, group filtering on every query |
| Cited sources | Yes | Variable | Yes, with a link to the paragraph |
| Hosting | Microsoft EU Data Boundary | Depends on contract | EU or UK of your choice, European model possible |
| Go-live time | 2 to 6 weeks | 1 to 4 weeks | 8 to 14 weeks |
Copilot also brings drafting in Word, Outlook and Teams, which a custom assistant does not replace. Many SMBs therefore combine a few Copilot licences for support functions with a RAG assistant open to all employees.
What a RAG assistant costs, item by item
| Item | Content | Indicative 2026 cost |
|---|---|---|
| Scoping and document audit | Source inventory, duplicates, permissions, priority use cases | EUR 3,000 to 6,000 |
| Ingestion and indexing | SharePoint and ERP connectors, chunking, vector database | EUR 6,000 to 12,000 |
| Answer engine | Hybrid search, citations, refusal when no source exists | EUR 5,000 to 10,000 |
| Interface | Web, Teams or intranet, history, user feedback | EUR 3,000 to 8,000 |
| Security and compliance | Entra ID SSO, group filtering, logging, DPIA | EUR 3,000 to 9,000 |
| Model usage | 10,000 to 60,000 questions a month | EUR 200 to 1,500 a month |
| Maintenance | Updates, quality monitoring, new sources | EUR 300 to 600 a month |
What sinks most projects is not the model but the documentation: outdated versions, duplicates, contradictory procedures. The initial document audit often removes 20 to 35% of documents before indexing.
Data security: the questions to ask
An internal assistant must apply the same permissions as your shares: a technician must not get an answer drawn from an HR folder. Require document filtering by group before anything is sent to the model, EU or UK hosting, no reuse of your data for training, and logs kept for 6 to 12 months. A data protection impact assessment (DPIA) is recommended as soon as personal data is indexed, and the EU AI Act requires informing employees that they are interacting with an AI.
Mini case study
Sarah, IT director of a 280-employee manufacturing SMB in Amsterdam, estimates that 180 staff search for documents every week, on average 2.5 hours. At a loaded hourly cost of EUR 42, that is 180 x 2.5 x 42 x 45 weeks = EUR 850,500 a year of search time.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
The RAG assistant is quoted at EUR 34,000, plus EUR 1,400 a month for usage and maintenance (EUR 16,800 a year). If the assistant saves only 30 minutes a week for each of the 180 users, the gain reaches 180 x 0.5 x 42 x 45 = EUR 170,100 a year. Payback: about 3 months. For comparison, Copilot for 180 users would cost about EUR 60,500 a year. These figures are a 2026 estimate, to be confirmed with a pilot.
FAQ
How many documents can a RAG assistant index?
From a few thousand to several hundred thousand without difficulty. For 50,000 documents, initial indexing takes a few hours and costs under EUR 300 in processing.
Can the assistant make up an answer?
The risk exists, but drops sharply when the assistant must cite its source and refuse to answer without a relevant passage. On well-scoped projects, the share of answers rated correct exceeds 85% during the pilot.
Can we use a European model?
Yes, European models hosted in the EU are available. Their cost is comparable, with slightly lower quality on complex questions according to our 2026 tests.
Do we need a pilot before rolling out?
Yes, a 6 to 8 week pilot with a team of 20 to 40 people, for EUR 8,000 to 12,000, measures time saved and answer quality before committing the rest of the budget.
Can the assistant query the ERP?
Yes in read-only mode, for data such as stock, order status or a customer record, always within the user's permissions. Allow EUR 4,000 to 8,000 per ERP connector.
Let's scope your project. Tell us your document sources, number of users and security requirements: we price the pilot, the full budget and an 8 to 14 week plan. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
