I've got a K4 750 with a Pamco in there.
Used to have a Dyna-S in there, set the timing, and rode another 25,000KM or so on it, then it mysteriously died. Well, it would die once the engine got hot, as has been mentioned by others here. That took a while to figure out.
Replaced it with a Pamco because I like the simplicity of e-ignitions.
Do I hate points? nope. I have them on my other SOHC4 that gets regular use. But I prefer the simplicity and 'set it and forget it' nature of the electronic ignitions.
to ME, the argument against electronic ignitions predicated on the 'it might die and leave you stranded' idea is kinda laughable considering we're talking about bikes over FORTY years old!! I can think of quite a few things that could fail unexpectedly while out on a ride. I've been stranded for quite a few reasons over the years. Only one of them was related to the Dyna.
My bike runs as well with the Pamco as it did with perfectly set points.
Run whatever you like. But to the original post - I wouldn't' pay that much for a used Dyna