You should be able to find a GS that year those miles with luggage for that price. Luggage is expensive, try to get a bike that already has it. Don't know about a rally tho. Unless that paint job is super important to you then I would find one with the options you want.
Additionally I don't know what your Credit is and all that but recently I was able to get a loan on a used GS with 2300 miles on it through a car dealer that was selling it and I got 2% interest so I think BMW credit is raping people. By the way it was weird I belong to a very good credit union and even they couldn't beat the rate the dealer's guy could get me through their bank, so you just never know.