There are probably no un-started Model 4 kits out there anymore, it's just been too many years since they were superseded by the newer, larger models.
I got my un-started kit for cheap from a widow, but it was a few years back. Also note, the model 4 came in a 1050lbs and 1200 lbs gross version, and the
1200 lbs model goes for a premium over the 1050 lbs. However, you might be able to find a run-down, previously flying model 4-1200 in bad shape, or wind damaged. One ready for recovering, and an engine/instrument overhaul, but otherwise has solid bones.
When you recover the plane, you could add the speed mods easy enough at that time. A guy in our builders group just got a Avid flyer model C for just $4500. ready to fly, but more ready to restore......
Hope this helps
Roger