One drawback to your evil plan ... lol
place order with supplier, but choose to pay later, then negotiate price. Instead of losing business supplier will adjust the price!
You can't pay later. The order can't be processed until you pay.
And if you could, it would delay the processing of your order by days or possibly even weeks. A good way to piss off customers and lose future business. And extorting the seller is not very polite either.
In my humble opinion ... just follow the usual and more polite route and negotiate with the seller after you have made quite a few transactions with them. Developing a good relationship with a seller helps a lot when it comes to problems or refunds.
If one followed your plan and one day you had to get a refund or some other problem, the seller may remember "
Oh, that's the rude bastard who tried to extort me by not paying and trying to force me to drop my price AFTER he placed the order. Fu#k him! I'll make him wait a week or two longer before I reply!" LOL
Be nice to your sellers and they will be nice to you. (
Drop-shipping Proverb of the Day) .