You're not going to find any DSLR for under $400 (unless camera tech has made leaps and bounds when I wasn't looking), so you need to get a camera with a good frame per second rate so you can just hold down the shutter and get multiple shots. Without a DSLR, single shots with a digi are impossible to time because of the delay.
Pretty much every shot I've taken for NS over the past two years was with a Fujifilm Finepix S5000, which costs about $350, has a decent zoom and 3.1 megapixels, but most importantly it shoots 3.5 frames a second (I think) for five frames. You can't make a good sequence out of it, but you can get some good air shots. Every shot in this article (www.newschoolers.com/NS2/News/ViewNews.php?action=showfull&news_id=859)
was with the Finepix. There's an option where you can hold down the shutter and it'll shoot until you release, then save the last five frames- so what I always did was shot while the skier approached the jump and was in the air, then released just before he landed: five good frames in the air.
'now i have tendanites in my achelles tendan in my other ancle' - skibrdingbitch