You get good tools at Halfords - their Pro set. I got a 150 piece set for £100. They are lifetime warrantied.
You get ratchet spanners, many sockets (included AF - you're going to need those for your Buell), torx bits (again - a lot of fasteners on the Buells are torx heads), those funny sockets that grip the sides of bolts for ones with rounded heads too. (can't remeber the name - Weisel or something funny like that). Oh yeah, it has universal joints and spark plug sockets too. You'll need them for doing the plugs on an XB.
If you look at the tools as a lifetime investment, they're not expensive - allowed me to do a lot of work on my bikes and cars I wouldn't have been able to do before, and saved the money.
Halfords Pro stuff is excellent quality - except for their Allen keys. The best I've come across are Snap On and Facom. These are an investment
Ask for a Halfords Trade card, on some stuff you'll get upto 50% discount
iirc on spanners and stuff, it's about 25% disc.
Any tools that aren't in the Pro range, avoid like the plague