Hi, In my opinion, MotorKart.com would go for no more than the registration fee at the wholesale level. You may have somewhat better success at the retail level. By the way, MotorKarts.com is available. That one has some limited type-in traffic and, in my opinion, would be able to get low $XX at the wholesale level. Hope this helps. BTW, if you have other keyword domains you would like appraised, sign up for the newsletter found at the link in my signature.
Are people more likely to search for kart or karts? Just a thought if the karts domain is available too.
GAdwords shows more exacts for singularis, and motor kart is more generic ( xqs my poor English ). I have an offer ( from people in this business, not resellers ) so I, really need an appraisal.