A couple of years ago I had a spray tan at The Tanning Shop, St Thomas' Street - right by the entrance to London Bridge station (opposite Guy's Hostpital). I seem to recall it cost £19 though it may have gone up since then.
I have had a few spray tans at the Tanning Shop on St Thomas' Street, I've always had half price vouchers but they are normally £25, they are cheaper if you book more than 1. Make sure you put plenty of the barrier cream on fingers and toes otherwise you'll be left with really dark marks on them!
I did it once and never again. We were going on holiday to the Caribbean out of season and it seemed like such a good idea at the time. Not only did it ruin all my clothes but I looked absurd. (AND I went to a woman who claimed to be Kate Moss's sprayer - yeah right.) As for what my partner thought - he was horrified and begged me never to do it again!
Lazy i - I don't recommend it