to be honest if you can get it 15p a photo I'd go for it, not too many at first to test the quality?
However I have to say the convenience of the service offered by Kodak on Kodak paper
may be worth the extra (49p per print). You can download the camera in the shop, or hand them a CDR & bob's your father's brother.
I couldn't find out, online, how much it costs at Boots?
In the first instance I think I would try a few options to see which gives the best result for the money.
Sorry - I havn't tried any services, myself, I had a look, inspired by your post - and was surprised how cheap it might be. Certainly competitive with inkjet printing - and won't fade!
- of course you could also do them on the colour laser at work!