Hello Brian and welcome to the forum.
Hats off to you for your efforts. Just a couple of thoughts for you to help you avoid any legal pitfalls going forward...
Who is responsible for warranty?
I'd hate to buy a lamp and then lose any potential savings if there was a fault. Or worse still, find that the cost of shipping and sorting a problem means I could have bought a UK sourced lamp cheaper. You can see where I'm coming from I'm sure.
So, are you going to be the supplier, in which case you're the person responsible for replacing the lamp FOC if it goes faulty, or do you intend to pass the buck back to the wholesaler?
As I see it I think you need to decide to be either a retailer or an organiser of a PowerBuy on behalf of a retailer. Each has obligations though.
A retailer has to make sure they can afford to replace any faulty lamps. The cost of that comes out of the profits. There may be an agreement with the wholesaler to recoup some of those costs, but that still leaves a portion outstanding for shipping costs, time etc. Or, as is common with Chinese suppliers, there is a No Returns clause in the sale which means they wash their hands of that responsibility in exchange for a lower price.
If you are organising a PowerBuy then you wouldn't have to shoulder the warranty burden, but your supplier certainly would. Would they be happy to do so? It also means disclosing your supplier's contact details and that might be something you want to check about with them first. They may be happy to do so, or it could cause problems; but it definitely needs to be discussed.
If it is a 'Not for Profit' PowerBuy then that means having an open book policy as far as costs go. In other words, you'll be giving all your time and effort free of charge for the collective benefit of forum members. Of course you'll also benefit from the lower pricing that comes from buying in bulk, but if you make a profit on the deal then you become a retailer and the whole warranty issue rears its ugly head again.
I think your intentions are great and wish you the very best of luck getting this off the ground. Lamps are an expensive item, mostly because of the cost of making such as precision piece of optical engineering, but still it's great to get some lower pricing in to the market just so long as the quality and reliability stay high and the usual consumer rights and safe guards remain in place. All I'm saying here is protect yourself, make sure you will have happy customers, and ensure that the reputation of AV Forums is maintained.
The very best of luck to you