I'm taking out an agreed to value insurance policy and for some reason they are looking for the cost of the trailer when it was new in 1973. I have no clue, I'm guessing around $4500?
Our 71 International Land Yacht 27' sold for $4,000 in 1973. In 1977 my father in law paid $15,000 for a 31' 1975 excella. You are probably a little shy but not much.