For $3k you can get a very sweet Kbike if you're willing to travel with a trailer or even fly/bus and ride. I think you'll have much more variety to choose from with a K75 just because they were sold in USA thru 95 and I think the 2v 4 cylinder Ks were discontinued here in 91 (someone correct me please). Also, I've been tracking Kbikes for sale for about a year and I'm seeing a lot fewer naked k100s than k75s -- there seem to be more k75s with aftermarket fairings, top cases, City cases and the like. For k100s I've been seeing a lot of RS and LT, generally not in as good condition as the better k75s on the market.
I got a very nice 94 k75 with 50 amp alternator, GIVI top case, Parabellum windscreen and perfect City cases, always garaged, for $2k. All I had to do was get a one-way Greyhound ticket and sit on a bus for 4.5 hrs. More often than not, the further the seller is from a dealer or a major population area, the more he/she will be willing to negotiate. It takes a huge investment in time and $$ for a buyer to travel several hundred miles for a bike...that's something most sellers recognize...especially since unless it's underpriced from the start, that bike is geographically undesirable and will be on the market for a long time.