1. Consistency beats a good day's rate
A supplier who is two per cent cheaper but out of stock in the week you need material has cost you a customer, not saved you money. Judge a supplier over a quarter rather than on an opening offer: how often was the material available, how often was the delivery on time, and how often did the quality match what was promised. Those three decide whether you can make commitments to your own customers.
2. Understand the scheme structure, not just the rate
In branded trades the base margin is thin and the schemes on top are where the earning is — quantity slabs, prompt-payment incentives, seasonal offers. Two suppliers quoting the same rate can be very different once schemes are counted, and a scheme that pays reliably is worth more than one that is generous on paper. Ask how and when scheme credits are actually settled, and get the answer in writing.
3. Credit terms are part of the price
A supplier offering thirty days at a slightly higher rate may be cheaper than one demanding payment against delivery, because you are financing a sixty-day cycle at the other end. Work out what the credit is worth to you at your borrowing cost before comparing rates. In a trade where working capital is the binding constraint, terms often matter more than the per-unit price.
4. How disputes actually get settled
Short deliveries, damaged material and rate differences will happen. What matters is what the supplier does about them. Ask an existing dealer, not the salesman. A supplier who issues credit notes promptly and without argument is worth a premium; one who disputes every claim will cost you more in absorbed losses than the rate difference ever saved.
5. Keep more than one, deliberately
Depending entirely on one supplier for a major line is a risk that only becomes visible on the day it matters — a stock shortage, a rate rise, a change of terms, a relationship that sours. Maintain a working relationship with a second source even at slightly worse terms, and buy from them occasionally so the relationship is real rather than theoretical.
6. Record every purchase properly
Supplier management is impossible without supplier records. Every purchase entered against a named supplier with its invoice number, date and freight gives you a payables ledger with ageing, a landed cost, and a basis for the annual reconciliation that otherwise takes an afternoon. It also means the next rate negotiation is conducted with figures rather than impressions.