elliott - as a guide, our holiday in Scotland this year is costing £550 for the chalet for 5 nights - this sleeps 6 - double, twin, bunk rooms, has log burner, sauna etc. Self catering. Includes membership to leisure club with swimming pool, soft play, tennis courts,golf course etc etc. and restaurants if you want that. Beside the railway line, and with views of the mountains.
Travel is petrol costs. Ski passes are £27 per day (adult) and £16.50 (child). You can get half day tickets which are a bit more than half price. Family day ticket is £74. As beginners you can get a reduced price ticket as you wouldn't want to use all the terrain available, and this allows you on the appropriate lifts. You can also get 2 and 3 day passes at £51 and £74 respectively for adults. I don't normally do this as the weather is sometimes unpredictable.
Ski hire is on top of this.
There is a package with one of the ski schools for 1,2,3 or 4 days tuition which is all inclusive (hire, lift pass etc) and this is £230 for adults and £190 for children, both for 4 days. I'm sure there are cheaper ski schools because this is the 'Cairngorm' one, but it's a guide.
So...
supposing you went for 5 nights, beginning of April.
You'd be looking at
Accommodation £550 + food costs
Ski-ing 2 adults @ £230
2 children @ £190 (assuming you wanted 4 days tuition)
Travel 250 miles petrol (say one tank each way) c £80
TOTAL £1470
That seems a lot now I've added it all up - I'm sure you could get ski hire and tuition a bit cheaper than that, but it's still less than the 4-6k for European holidays!
Sorry this is so long! I'll have a look around for cheaper ski schools!