Groupon & Printerpix photobook deal

With a holiday coming up in the next few weeks I bought a voucher from .com offering a leather (value £34.99) for under £10. Postage would be £4.50 extra but the idea of such a book at £15 is surely a great deal. 

I laid out the book opting for a bigger book for a bit more.  Ultimately I paid £25 which is fair enough and the fee shown in the invoice here is correct.

Printerpix however do their VAT calculation oddly though. VAT should never be calculated before the discount so it seems to me that P'pix are paying HM Gov too much VAT. 

That point aside, the final product was good. I felt a lack of control laying out the book so it wasn't as I'd wanted. While Printerpix offer lots of page layouts there just weren't enough landscape layouts. It seemed that if you needed more than one landscape picture on the page you feel you're losing photo space and gaining blank margins. I've done a dozen of these books with great results but the Printerpix interface could be better. As could the maths.

Comparing the two services: 

Printerpix 26 pages; thicker paper; black leather cover total cost £25 with Groupon voucher
Snapfish 34 pages; regular paper; black linen cover total cost £23 with 50% offer