Well out of the toy budget of most folks, but I've seen them in action and they are top notch quality and pack a ton of processing power. Assuming somebody is ready to shell out 400$ on a HU and another 500+ in outboard processors it's not that far out of line price wise since it realistically replaces that much stuff that some folks would buy and greatly simplifies the signal chain. Less things in the chain = less potential for weak links.
The 80PRS is a very solid value and if you shop around online can be had for a reasonable price. Really I don't know of anything with more processing power than the 80 until you get into the 99, so it's about as good as you'll get without really breaking the bank.
If I buy a HU and use it for a couple months and sell it for a 60-80$ loss I chalk it up to the cost of "renting" or auditioning it. Can't be helped, and if you're buying good quality gear, shopping wisely, and don't beat things up you can usually get a fair resale value on equipment.