Where can I buy iphones 4 32 GB in bulk ?

I want to buy iphones to sell to others, I’ve been trying to find places to buy them at a good price so I can resell them but they are way too expensive, you can’t get a profit out of itm I tried ebay and it’s too expensive, I would like to know where this people get the phones from and how can you buy them at the prices that they do? I’ve had an iphone from China but I don’t want those, I want the authentic iphones made by Apple here in the US, if anyone could guide me I would really appreciate it.

Thanks.