I just recently purchased a rack from Rocky Road - I think all up to my door was $436 US for the full rack and the tyre holder, and the shipping was $410 US (Dont listen the the quote it gives you when ordering - Contact Rocky Road and they will give you a more accurate quote for shipping).
So was still $850US approx, but it is solid AS! The way it mounts onto the roof I would be surpised at the weight constraints you are mentioning. Im testing now to mount a rack on top of this roofrack for a bit more space.. As when you put the spare tyre up on the rocky road rack, there is only limited space. I have an Oztent i travel with, and its hard to fit that alongside when the spare wheel is up there. I managed to find the top rack secondhand for $170, so not a bad setup for just over 1k.
