I've bought dozens of books from WeBuyBooks and find them to be trustworthy and reliable. I've only needed refunds twice and had them both dealt with promptly and fairly (this was for sales on their eBay shop). I've sent a couple of boxes to them so far of my own books and felt I've received a fair price in return. Not a fortune but that's to be expected and it's far easier and nicer than other options e.g. carboot sale. So in my experience, a good service all round and would recommend