Good source for used iPhones?

[North86]

Looking to upgrade my kids' iPhones. Since I have to get three, I have no interest in a newer model, but want to get at least a 7 or better.

Any recommendations for a good source for used phones?

TIA

[Casual_Shooter]

I used Swappa when buying my daughter a new phone but did not have a good experience. The touchscreen of the phone I bought did not work. Took quite a bit to get the seller to refund me my money. Turns out he ran a phone repair shop, but was selling as an independent seller.

From the site's reviews, I don't think my experience was typical.

Also I was leery of whether or not the phones I was looking at had their screens replace even though they were not reported to have had that repair done. Not an easy way to tell that I know of.