I know that to eat on the slopes is pricey for what you get. It's been a while since I've been there and we always packed a sack lunch and took it with us. I would guess maybe $20 to eat at the slope and probably twice that for a nice evening meal, depending on how nice you want to eat. I'm sure that there's cheaper meals and I would check on the internet to see what's available.
Here's a few restaurants that show their menus and prices. There's a pizza place that isn't too expensive.
http://summitactivities.com/grand_wi...estaurants.php
http://www.skicoupons.com/coupons.cfm/r/9/g/7/cc/1
Winter Park is a great place to go skiing. We've been there several times and my daughter is begging to go back again this year!