In reply to Legs:
Try Skimium for cheap deals on gear - I've used them a couple of times and they've been fine. Chose resort and what you want and book it in advance online.
Try places like TK Maxx or outlet shops for cheap ski jackets. I'm on my second Trespass one (I ripped the first one by snagging an unzipped pocket) and it only cost something like £50 in a sale.
Dedicated ski jacket is handy, as it will have a snow skirt and lift pass pocket on the wrist, which makes it handy to swipe the gate - double handy if you snowboard and the sensor is behind you.
I'd generally say a ski jacket is too baggy/bulky/hot and the wrong cut in the shoulders to wear mountaineering. On my first ski trip, I used my Sprayway mountaineering GoreTex with a fleece underneath - you'd be better buying a mountaineering jacket and using it skiing. I've also skied in a mountaineering soft shell - see my profile pic to prove it.
Post edited at 15:16