FedEx Freight has about the best prices on stuff this big, at least in my area, that I've found. I've used them to ship packaged sets of 5 wheels + tires, a 327 boat motor, etc., etc. Their rates aren't as expensive as you'd think.

You have to pack it yourself, though, which is a PITA. You're going to need to buy a crate. Once it's packed, you call them and they send a truck to your location for pickup. I think UPS also offers a similar service, but I've not used it.