Do not trust the offer price, as even if you have a 100% prefect phone, they will definitely take off at least 10% of their offer.
I sent a perfect phone to cashmyfone, with no external damage and in total working order. After 6 days of hearing nothing from them, they emailed reducing the price by 10%. They offered no explanation as to why. In my view they didnt offer an explanation because there was no reason to deduct other than the fact they were ripping me off.
I would also note that i then tried contacting customer services several times over the course of a 3day period in which i never got a response.
If you are willing to take at least a 10% hit on the offer price and wait a long time to receive your confirmation email and monies then they may be okay to use. If not, forget them...