K1 aero quite different from K1, aero comes with big bore shocks, gear diffs and a re-designed motor mount and top deck and a re-designed body shell as well as 12mm hex wheel fitment all round, I would dismiss the original k1 and look for a K1 aero as the price difference is not that much but would cost a lot more to convert to the current car buying the parts, usually a few here on Oople for sale or eBay, easiest way to tell the difference is the centre layshaft/motor mount has 4 screws through top deck on the K1 aero and the k1 has just 2 screws
Schumacher has a new 4wd car released a little later this year after the worlds events so lots of K1 aero models will be for sale soon
There are a few on eBay at the moment, for a k1 aero with a few upgrades fitted around the £150/180 price range is what you should expect to pay for a rolling chassis
Hope this helps
