I assume that you already belong to a gliding club. Talk to the other members and as previously recommended, the CFI in particular!
Most gliders belong to syndicates of 2 or 3 people. There may be already a syndicate at your club looking for a new member. Syndication splits the costs and guarantees that someone will come to haul you out of fields!
p.s. by choice I fly a wooden "vintage" glider (Slingsby Skylark 4). It's Annex II so has lower CofA costs (BGA fee is £89/year. Inspectors costs would be on top but then I've got an inspectors rating so only have to buy myself the beers!) The hull value is so low that I only have 3rd party insurance of £2 million which is £195/year. Again it probably helps that I've also got an instructor rating.
In reality you can spend as much or as little as you want on gliding, depending on the kind of gliding you want to do. Club membership costs vary enormously so do shop around if money is tight.
Last edited by astir 8; 8th May 2012 at 12:53.