I know it isnt really any help right now, but Eureka (
http://www.eurekacampingctr.com/eureka/) in Binghamton New York has a HUGE sale every spring. Even their regular price is phenomenal. I get all of my "high price" items there. Both of my backpacking tents have been bought there, one a Solitaire, the other is the Zues 2. Neither are a 4 season tent, the solitaire I never liked taking out if it was cold or rainy, but I would not hesitate to use the Zues in the winter. With the Boy Scouts, I participated in at least 2 winter camping trips each year, and if you do it right, its the most fun you can have camping in my opinion. I have 4 sleeping bags, depending on weather, a 50*, a 15*, a -10*, and a wool bag I made, and depending on temperature I plan with them. I have been comfortable with the 15* bag at -27*, with the proper planning. Dont clear the snow out from under the tent, snow is a very good insulator. It was mentioned earlier, but even if you feel dry, wipe yourself down with a towel and put on fresh clothes before getting in your sleeping bag. Even the tiny bit on moisture on your skin will chill you. A trick I learned before everyone found out about the side effects was putting boiling water in nalgene bottles, wrapping them in a towel or shirt so you dont burn yourself, and putting it at the bottom of your sleeping bag works great. little extra heat and doubles to hydrate yourself. I believe Bill mentioned about sleeping pads and air mattresses. "Dead Air Space" is what insulates you, so you want to make sure you have something under you, closed cell foam pads work great, but they take up a lot of space. THERM-A-REST makes inflatable pads that pack down a lot smaller and give you a little more dead air space. They also make some that are 3/4 length for backpacking, they make them tall, and they make some that are I believe 3" thick. I try to stay away from air mattresses because they take up a lot of room and dont benefit you (insulating wise). Other helpful tips, get a pair of winter boots with removable liners and bring them in the tent with you, lay those and your outer gear on your sleeping pad, put a water proof barrier on that, then your sleeping bag-it helps keep everything from freezing and a little warmer for you when you wake up, DRESS IN LAYERS! Try not to sweat and remove/add layers as needed. Try to avoid wearing cotton, at all. Synthetic fibers wick sweat away, keeping you dry and warm. Wool has some special property with a fancy name I dont remember, but it means it maintains its insulating abilities even when wet. Cotton soaks up water and holds on to it. Always try to wear a hat. Your body naturally keeps your head and torso warm, the rest of your body is second. If your head gets cold, your body will pump more blood there, and less to your fingers and toes, causing them to be cold. Many times Ive dealt with people complaining about cold hands, bundled up with the warmest jacket and snow pants and boots and mittens, and no hat. Oh ya, Mittens are a wonderful thing if you can deal with no fingers. I usually either wear or at least have both when Im doing the whole cold weather thing. If you couldnt tell, winter is my thing. Grew up in Upstate NY right in the middle of the lake effect snow belt and did a lot of camping up in the ADKs. Wow. I typed a lot.