I've had a search on this forum to try and find the answer to my question but none of the threads have what im looking for... I've got a 2G touch and I want to get an iphone 3g. I can get a 16gb one from ebay for about £300 which is great for me. The question is... if i use my current 02 sim on the new iphone (pay as you go), how much is 3g going to cost? I know its free for a year if you buy one new from a shop... but what about if i buy a second hand one?