Ebay have banned the selling of e-cig stuff on ebay (and have done for ages) so if the people selling stuff on ebay are bending those rules it makes me wonder what else they might not care about.
I would take the Andy up on his offer. A quality eGo battery (not a shisha pen) will set you back around a tenner. If you get a VV one then a little more.
JoyeTech, SmokTech, Janty, Vision or AnyVape are all good quality brand names for those kinds of batteries and you can find them in lots of places online .
One of the things that e-liqquids sold on ebay need to do to get around the ebay rules is not contain any nicotine, it's entirely possible that the e-liquid you have is zero nic. that doesn't explain the lack of flavour, but you might not have been getting what you were expecting.
Like Skitty says take longer slower draws on an e-cig than you would a tobacco cig as they work slightly differently.