Quality of tools like cone spanners, BB tools and cassette tools should not be compromised. There's no way I'd get a cheap tool for any of these tasks. Cheap tools are less likely to be manufactured to close tolerances and are therefore more likely to slip off cone nuts, etc. and cause damage to surrounding components, or simply frustrate you in the middle of a job by having to trek to the store and buy a replacement.
The non-specific bike tools I use the most are good quality, but not workshop grade. I use Stanley spanners, 8mm, 10mm and 15mm are pretty much it on my bike, and also have a set of GS (German quality standard) grade ball-end Allen keys. The spanners are between £3 and £6 each and are more than adequate for regular use. I paid £7 for my 10pc Allen key set, 1.5 mm to 10mm and, again, are adequate for regular use. I have a good quality socket set from my motor mech days but honestly wouldn't be able to justify buying one for bike work, they just aren't necessary.
If you're going to spend all day, every day fixing bikes than it's worth spending big money on tools, otherwise it'll probably work out cheaper to use mid-range stuff and replace it as it wears out.
It might sound strange but go to different tool shops and handle different tools. You'll soon get a feel for what's good quality, and what's not. Also, bike shops are rarely the best place for non-specific tools. In the UK, I've found that things like tools, lubes and oils all have a huge mark-up just 'cos the packet has a silouette of a bloke on bike. A good quality allen key set costs £6 for a Stanley in the hardware store, yet it'll be £12 for a 'multi-tool' with anodised, laser-etched whatever.
If you have, and service your own, suspension forks, go to a motorbike shop for oil. Guaranteed it'll be way cheaper without losing out on quality.
I'm also starting to rant?!? I'm off....
