A good supply-house relationship can be worth a lot. Periodically comparing a few common purchases can still be a useful business habit.
Compare the whole purchase
Use the same part number or an approved equivalent. Include delivery, availability, returns and your actual account price. The cheapest listed item may not be the best option for that job.
Start with a small list
Pick frequently used materials and compare them consistently. A spreadsheet may be enough. Where distributors offer supported feeds or integrations, a tool could help gather prices, but account-specific access needs to be checked.
Keep someone responsible
Confirm specifications and stock before ordering. A search result does not prove a part is suitable or available for pickup.
Would an occasional comparison of your common purchases be useful, or does service and availability drive most of your supplier choice?