We just bought a tent this weekend at Sears. I love EBay too, but found their tent prices were outrageous once shipping was added on. I looked at other places and the prices were not any better, and the S&H was so high. (checked brand and style to other stores in comparison) We'd rather just buy it in the store and take it home =)
Sears had some online that were on sale last week... they had a 4 person, 65 sq ft tent (9x11 I think) for $40, marked down from $70. Decided to go to the store adn check it out, and they had lots of tents onsale, and we found one on clearance that we bought - its 120 sq ft, 7 person, 3 room for $46 - marked down from $159.99. We were amazed! Much larger than we need, but easy setup, same price as the ones half the size, and we can never have too much space! Esp in the rain!
I honestly don't know anything about good tents for harsh conditions, but this one is really nice, has a rain tarp, etc. I would think the sleeping bags would be more crucial for the warmth aspect than the tent itself... But i could be wrong.
Anyways, check out bass pro shop, target, academy sports and outdoors, sears, etc. Lots of good deals! =)