A great way to get my repeat business is to be honest. Example - a bullet supplier (that's the lead bits that come out of the dangerous end - not the whole cartridge) - web site shows no stock (this is a few years ago when the "OMG the dems are in power" stupidity was going on).
Phone up -
"can I have some"
"there's a reason we're showing no stock"
"yeah - I know - but I'm out"
"Hmmm - how many do you need"
"Couple of thousand - normal order"
"No - how many do you NEED - not want"
<thinks> "150?"
"OK - we can do that - be with you this week"
They've been getting my regular business ever since.