The value really depends on the boat. If it's a Hobie 18 then its a little on the high side, if it's a F-18 then its a pretty good deal assuming everything is in good condition. But that broach float on the mast makes me think its a non-racing Hobie.
Does it come with a trailer, dolly, sails, rigging, all of these can add substantially to the value.
Looking at Prindle 19 images it seems there are some differences, principally in the area of the forward crossbeam, and the rudders look slightly different. Could be something else that always had a forward tramp.
But seeing as OB is a Prindle owner, you probably should listen to him..
Not exactly true - dinghys (I include small cats) seldom if ever have titles. The trailer does because of road licensing but seldom the boat.
Around here the cutoff is 10 meters/10 horsepower - below that you require no documentation and even above it if you only license it (K number) it gets recorded as whatever you put on the application documents.
It's a surprisingly casual system for such expensive things but I guess it works well enough that no-one has seen the need to tighten it up.