The suggestion someone else made about coming up here midweek is a good one, also avoid holiday periods.

If you want to stay in a hotel, motel 6 is the cheapest, find them at: http://www.motel6.com/reservations/motel_detail.aspx?num=0369 and If you are looking for an inexpensive cabin try Cool Cabins they have the best rates for a cabin rental company, you can find them at:
http://www.bigbearcoolcabins.com/

You can eat really cheaply at one of the fast food places or go to Vons and get groceries and eat where you are staying. If you want one of the local favorites for breakfast go to the Grizzly Manor on the Blvd they are cheap and they have huge portions. I recommend "The Mess".

For Ski and Snowboard Rentals you have to Go To Goldsmiths Boardhouse. They are located on the corner of Big Bear Blvd and Moonridge Road where you turn to go up to Bear Mountain. (909) 866-2727 They are the cheapest and have the best service and quality Gear. Go to this page of their website to print a coupon and get a 10% discount for everyone in your party. http://www.dataroad.net/goldsmiths/coupon.html
They are about half the price of renting at the resort.

If you know anyone who wants to buy or sell real estate in Big Bear Please send them my way.
http://www.big-bear-real-estate.us/