You won't start getting 'sweet deals' until you are at least level II. Level Is can get some discounts, but not what I would call 'sweet deals'. The free skiing thing is also a myth at most areas. I just got my level III last year and know of 1 area that does free tickets for level IIIs.
Get certified cause you like teaching and want to get better, not for the deals. If you want deals, work at a shop. They get better deals then PSAI anyway.