I have at least 15 in various states of "health". All fill a room upstairs waiting for me to work on them. I recently got a White treadle in a nice 7 drawer oak cabinet
for $70. Some have good machines, some have only decent cabinets. No more room! I find them on Craigslist. Freecycle, and even on the road after garage sales. I like reading the vintage sewing machine thread on this site. If you read sites about treadles on the Web you'll be able to decide what machine you'd like and how much restoration you can handle. Then you can probably find a good machine you can actually use for less than $100. And- many of the old treadles are a lot like the old VW's- easy to change parts. Have Fun!