Bookseller Watersones website is no longer connected to Amazon as it used to be, they are now going alone - and seem to be making a good job of it!
They offer free delivery to store on any item, or free home delivery when spending £15 or more. Looking at the first Books page on BillyBargain, Waterstones comes out cheapest for all 10 items - in some cases even when you pay the £1.50 delivery charge! Some deliver to store prices are the same as WH Smith deliver to store prices, but it's nice to have another option!
For orders under £15 they charge a flat £1.50 for home delivery regardless of the amount of items (provided you have them sent all at the same time) as opposed to Amazon's £2.75 plus 59p per additional item.
I didn't realise Watersones did a deliver to store option, so thought I'd just give a heads-up!