Moved to LFC Discussion, as this isn't really forum news or feedback
Every site that sells tickets does so at a very high price. Your best bet is to buy one from a tout outside the game - I generally find I pay about a 50% markup - but this is obviously not a guaranteed ticket so you might find it a bit risky. You can try these guys
, like all the sites they're expensive, but I know people that have bought tickets from them before & at least they seem to be good with delivery etc.