Yeah race karts are very popular in Europe.
I remember you've been searching your craigslist already. Since C/L doesn't have a category for go karts, sellers post kart ads in several different categories so its sometimes difficult to find them all. So make sure you perform your C/L searches using all the commonly used (mis-) spelling terms besides just
go kart. Also enter the search terms:
gocart, go cart and
gokart (plus substituting the term
shifter in place of
go) to help find all the kart ads.
You could also start checking craiglist ads from other towns you'd be willing to drive to for a bargain. (if you found someone selling a nice $1000 shifter chassis for $300, It'd be well worth spending $100 or more on gas to travel and pick it up)
You should also try to check the C/L ads several times a day. When sellers price stuff way below its true value, there's usually savvy buyers that snatch up the bargain within the first hour of it being posted...
I'd also recommend you start posting your own C/L ads titled something like:
Want to buy Shifter/race go kart. Sometimes these wanted ads will trigger guys (that don't want to post their own ad) into selling their kart. (make sure you include all the other search terms in parentheses at the bottom of your ad to help everyone else find it) You could also post your wanted ads in other towns craigslists but you'd have to change the wording around becuse C/L doesnt usually alow multable posting of the same ad.
Here's a couple shifter ads I recently ran across out here in AZ:
http://phoenix.craigslist.org/evl/rvs/1621608639.html
http://phoenix.craigslist.org/wvl/mcy/1619855560.html