Excuse me if I'm wrong, but the whole scenario sounds ....
almost impossible.
- You've been a member here for over 4 years and you have no idea yet, where to buy your supplies ??
- You also state in your profile that you don't have a company ??
- Why would you only want to buy supplies for around the inside of your shop ??
I know I usually doubt those that keep everything a secret, but perhaps you are coming across to the various distributors as an end-user and don't deserve any discounts, let alone the opportunity to buy at a sign shop's discount. The mere fact that you dealt with one company and the only guy that would give you a discount is gone and now no one will help you is suspect, to say the least.
Do you have a business license, EIN,tax exemption number or any references when they ask for credit references ??
Perhaps when you say your customer saw the catalog and saw the prices... you are actually talking about yourself, because........ in the next post, you say these products are for you and make no mention of needing a discount to turn a profit. It sounds more to me that you want
OUR discount, now that you've come across some new suppliers.
They won't give our prices to an end-user in most cases and even if they would, an end-user is not going to buy a roll of vinyl for one small job and then throw it in your face about a few bucks. Could/would you explain a little more ??