The best part of open air (360deg spherically in a tree!) camping is that your sleeping gear will always have some sorts of detritus from the tree in it. I love getting into my gear, the smell, the grit, the reminders of nice nights in the tree from the leaves and twigs.
Don't sweat the small stuff, everything gets dirty eventually. It's the second law of thermodynamics afterall...everything moves towards disorder.
I stick with CHEAP gear too. Check CAMPMOR, they had some really good deals on low temp bags recently. When you don't pay as much you don't worry as much about using it, at least I don't.
Long stort short Jim...go sleep in a tree, once you do, I bet you'll either love it so much you'll have no more need for excuses, or you'll hate it enough to keep to the ground.
Climb Safe!
Sleep Warm (it's warmer in NC!)
Icabod
Cam "Icabod" Taylor