Goldstackers, just like all the other dealers here work hard to give us all access to trustworthy supplies of PM's in order to build our stack - and from my conversations with some of these dealers, there's very little in the way of financial reward for them - they're keen to get the best possible prices for us, and pass on as good a price as they possibly can.
Honestly, I couldn't support the idea of giving a reward to folks for doing what they're supposed to do (and agree to!) in the first place... that is, place and order, and make a direct deposit (or other accepted payment) in time.
Heck, I make the transfer within 5 minutes of getting the invoice, and I do that intentionally to get the cash to the dealer as quickly as possible to help them who help us.