You're not going to like my advice, but here it is anyway...
I personally would never buy a refurbished piece of electronics. You are opening yourself up to a fair amount of risk. It it breaks down, the money you saved by buying refurbished would easily be lost in repairs or replacement.
Buy new from an authorized dealer. If something goes wrong under warranty, the retailer and/or the manufacturer are the ones at risk, not you.
If you can't afford the receiver you want as a new item, buy something less expensive or wait until you can afford it. Sort of a "save now, play later" strategy.
Refurbished sounds like a good idea b/c of the money you might save, but in the long-run I suggest that you will not come out ahead.