Ok. I've wanted a Dyson forever. But I can't justify spending $500 on a vacuum.

So I need some less expensive alternatives. It must be bagless (my lab produces so much hair i'd be changing the bag twice just to do one room!)
Must have a HEPA filter (i've got terrible allergies/asthma).

Any recommendations??

If no one has better recommendations, I'll just suck it up and buy the Dyson. I got a coupon from Bed Bath and Beyond for 20% off, so that'd bring the price down to a meager $400. For anyone who has one, what is the main advantage of the "Animal" model over other models? It's just the attachments, right? Do you think the upholstery cleaning attachment is worth it?? I do have a lot of hair on my sofa...