Yeah that was from a honda dealership that was the 1st of only 2 trips to then second was for a service that they then told me the car would fail its MOT on bushes, back box and all four tyres - granted back box was f**ked i knew that, they wanted £100 odd for one, i got one fo £19 all four tyres - them round £200, my local fitter £130 for the 4 (only 1 would have failed the MOT) bushes cant remember how much they wanted but they still hadnt been changed nearly 4 years later when i sold the car.
Re alloys-
you need to know the PCD ( think its pitch circle diameter) basically the distance between the wheel bolts. on 4 stud its the centre of 1 stud to the centre of the stud opposite. on 5 stud its from the centre of 1 stud to the middle distance from the 2 opposite.
Also the ET ( from the german Einpresstiefe meaning insertion depth )more commonly known as the offset )
and the bore size
have a look at
http://www.carlsalter.com/wheel_fitments.html
it seems to give a good guide
i would say with most of us its a passion for cars. there are a few full time mechanics here a a complete nutter ( ok someone with toooooo much knowlage and too much time

thats Oldgit by the way )