1. Im no expert and Im doing OK

2. The only tools Ive used out of the ordinary are my power mitre saw for cutting ali (cause Im lazy), and a £20 reciprocating saw for cutting the plastics. Otherwise, all Ive really used is a drill and a BFH

3. Rough costings for whats in omicron (not counting stuff Ive bought and not used... which we all do):

Radio gear - old stuff - new would probably be £70
2xel cheapo cordless drills - RRP £13.99 each (free from sponsor)
Aluminium - £5 from scrapyard
5mm polypropylene - £20? for a big sheet (Altec plastics)
2mm polypropylene - £18? for two big sheets (Altec plastics)
3 electronize controllers - rrp £30 each from technobots, I had an old one lying around.
Link - £5 - Stu
Drill Mod kits - Dom
Spinner motor - £10 - Technobots (now discontined)
Steel - Lying around shed coverred in rust.
Misc nuts and bolts - Free from sponsor (Wilsons agricultural), probably would have cost about £6.
LEDs - 5p each
Resistors for LEDs - naff all
Spare xtals - £30, but I have more than most people

So, about £250, if you use what you have lying around, you can do it for less, or you can get silly with things.

If youre using nicads (drills come with OK-ish ones, you can eiter use the drill charger, or get a perfectly servicable charger for £50.

Or as Geoff says... you can spend silly money

Dont know about maintaining, I have a spare drill and weapon motor. I have enough material to fabricate another couple of chassis in what I bought in the first place (might actually measure them first next time!).

Oh, and if you havent worked it out yet, BFH is an IT term for a Big Fn Hammer