If I was doing this nothing would be below 20 that is a complete kit. Walk into a store and buy one for 15. Being this is for insurance and you are covering your assets do not sell your collection short. Even parts have value. With kit bashed kits the value varies as we all have our own interests. You may never build that street rod you plucked the engine from but it has trade value to someone who would like to use it. So I would put the parts kits with just engine and tires missing at 10 at least, if it has no body just 5. Sorry if I am rambling BTW.