usually bikes go for about £50 more on eBay. I've found that you can haggle prices on PinkBike, but it's completely up to him.
Onza make strong bikes for beginners to bash around, and that's important. I wouldn't tell a beginner to get a thousand pound lightweight bike, because chances are that it'll break within a couple months...
If i'd wanted to start on a 26" bike, i'd've probably gone with a hitman, to be fair. especially if it's single-speed.