1 pair works, 2 is good, 3 is great, but 4 is amazing!
park (mostly cambered 70-90 waist)
pow (100-130 waist fatties with hella rocker)
rock skis ($40 beat to shit park sticks you find at a swap)
touring/tele (entirely optional for some, the only way to ski for others (no lifts??), but If you're into hiking up, nothing beats a sick telemark or AT setup)
i love my 4 ski quiver:
APO hutches
Volkl Chopsticks
Armada AR5s ($60 at swap)
amazingly light G3 tele skis w/ skins (just getting into touring since finding a $50 pair of sick G3's with skins at a swap-- saving up for Tele boots!! STOKED!)
I can't imagine having more skis than 4 pair.
Although it is fun to have drastically different styles of ski, because then you can use the whole mt., and getting on a different pair can be like re-learning how to ski!
convince them by showing them a video of Eric pollard, then telling them that you want to land switch in the pow, and that you need a new pair of Opuses to do that haha.