It's way out of your price range but Snowtrekker makes great tents and if you find yourself working in cold weather, adding a stove makes life downright pleasant. I have the 10x13 Crew for use in all seasons. Very roomy for 2 and palatial for one. No floor but some good tarps and wool blankets make for a comfortable space.

again, spend but will last a long time and also self supporting.