I don't have much to add, but this thread is great.

I don't have experience backpacking, but I have been car and boat camping for over fifteen years now. I've used plenty of cheap tents over the years. Many were loaners or gifts. I've camped in extrema rain storms, sometimes for more than a week at a time, with them and was able to stay dry by implementing tarps, bungees and ropes. I've never used an expensive tent, but from my experience I would say that it's probably cheaper, and a time saver in the long run to get a nice tent made to endure the elements rather than buying a cheap tent, and combining it with tarps etc.

That's just the thoughts from my experience though, to each their own.