I know...here I go digging up another old thread. Sorry, I just wasn't around here when this thread was fresh!
I don't get it either. My experience is really almost all with Doodle Bugs, but this could just as easily apply to a Simplex:
-$5000 seems to be about the upper limit of what I see them listed for when restored to pretty close to correct.
-Most are actually selling in the $3000-$3500 range, done, complete, and running. Often with accessories, too.
-In most cases you can't even buy just the parts to restore your own for $3000.
-A professional restoration (including a real engine rebuild) will be $6000+ and that doesn't include the cost to buy the bike in the first place.
-Loose parts prices on places like Ebay are getting to be just out-of-sight high. A good, correct scooter could be parted out on Ebay for 2x what people are willing to accept for complete scooters, so they're leaving money on the table, I guess. It could be argued that there is more demand for the parts than there is for complete scooters, but then again, if the parts are "worth" that much, having them all together and on a scooter should make them "worth" no less, right? I don't want to see folks rip apart nice complete machines to part them out.
Overall, I just don't understand why someone would be willing to let a complete bike go for so little when the parts & restoration costs are so high.