The short answer
Evaluate a distributor on what it will put in writing: minimum quantities by product, how availability is stated, how allocation is decided, what happens when a date moves, and whether it competes with you in the consumer channel.
Most shops compare distributors on price, and price is the least informative variable available. It is easy to observe, easy to quote favorably, and almost never the reason a relationship works or fails.
What actually determines whether a distributor is useful is availability, flexibility and honesty about both. A distributor two per cent cheaper that cannot get you the product, or can only sell it in a quantity you cannot use, or tells you it is arriving on a date it already knows is wrong, costs you far more than the two per cent.
The questions below are the ones worth asking instead. None is unreasonable, and how a distributor answers is as informative as the answer.
Flexibility is the most commonly claimed and least commonly delivered attribute in this industry. The right questions are specific.
Every distributor gets dates wrong, because upstream dates move and nobody downstream controls them. The difference is what happens next.
Allocation is where the largest differences between distributors show up, and where the least is usually written down.
Two questions matter more than their brevity suggests, and both are about conflict of interest.
The first: do you sell to consumers, break product, or operate a marketplace presence? A distributor with a consumer arm is a distributor whose interests diverge from yours on exactly the products you both want. Some do it and are upfront about it, which is at least workable. The answer to avoid is a vague one.
The second: what are your payment terms, and are trade terms available? Prepaid is normal for a new account at any distributor and is not a red flag. Being told terms are available and then finding they are not is.
Finally, ask what they will put in writing. Not as a challenge — as a practical matter. A distributor that publishes its allocation criteria, its return policy and its preorder terms has decided to be held to them. That decision is the most reliable signal available about how the relationship will go when something goes wrong, which it eventually will.
More than one. Different distributors carry different lines, receive different allocations and impose different minimums, and a store with a single supplier has a single point of failure on the products that matter most. Any distributor advising consolidation is describing its interest rather than yours.
No. Prepaid is normal for a new wholesale account anywhere in this industry, and a new distributor offering open credit freely is taking a risk that should concern you more than the prepayment does. What matters is that terms are stated accurately rather than promised and withdrawn.
Ask what they do when they do not know a date. A distributor willing to say "we do not have a confirmed arrival" is one you can plan cash against. One that always produces a date has invented at least some of them.