You don't need a budget, you need a stratigy.
You've got the cloths, you've got the skis, boots & poles. Go for the season pass. Great value if purchased now since you still have a whole ski season to amoritize it over ($500/6 months = $83.33/ month). By buying now, you can show your loved one that you are wise in getting the best value for your money. After all it would be a shame not to recope the cost of that season pass. "Gee dear, you didn't let me go skiing the 20 times it would take to break even (OK the math is off 12 times, but a little streching never hurt). You kept me from getting the full value for the money. It's your fault it got waisted" (Turnabout is such fun sometimes). In these analysis, I never include the cost for the day trip to the mountain, or the annual trip to Utah (We stay with friends). Oh the car get miles on it but what a way to go. There are ways to economize.
Other suggestions --
Buy last year's best gear at the end of the season. Make friends with the ski dog at the local shop and get him to hold you a pair of those dream skis. My boots Lange, V7's $180 (I paid for a custom fitting on them, another $100). Ski's, Volant T3 Powers plus Look P-8 bindings, $450. Hit the ski cloths outlets. I hit Northface's Outlet seveal times a year. I just purchased a liner, skijacket & skipants for my youngest son for $150. Top quality gear from the samples rack, gortex too. Purchase your SUV from Hertz. A couple of years ago I picked up a Montero Sport for only $16K. For the kids I buy rental or demo skis. The bindings adjust to any boot. It takes a while to find a good pair, but it can be done. I worked with a shop guy last year and picked up a pair of Ross 10.4 Cut's and Volant Gravity's for the kids for $250. The big hit was the boots, 2 pair, $450 including the custom insoles.
Big trip to Utah last year in December, borther paid the gas, and food. I used frequet flyer miles to pay for hotel(Fiends were in Canada skiing of all things). Plus we took advantage of the ski discount $20.02 discount coupon deal. Try skiing Alta for $18 a day, PC for $28.
Hit the co-marketing stores, I get $5-$15 off of lift tickets for the days my season pass was blacked out. McDonnals $5 off at Sugar Bowl. Alberson $15 off Heavenly Valley.
Buy value based season passes. I purchase the one from Kirkwood that excludes Christmas Vacation, and the two holiday weekends (Usally not the holiday it's self, guess when I go ski?). In that case I go ski somewhere else for variety. I must have gone up to that mountain about 20 time last year. I got my value.
This year with 3 season passes and all of the gear, its just a tank of gas up and back plus food. And if they want new ski's for Christmas, well, that comes out of the Christmas budet.
There are ways to feed the passon on a budget.