I have now completed 64mi/104km on the budget Peugeot (over multiple rides).
Bike 30:
tube from another bike & computer battery 5
Total: 35(usd) for 100km of riding within 100 days

Only problems were loosening friction shifters and in the last few miles a weird shimmy in the steering which I hope is a bad tire.

I have a new set of tires ready to be installed, and I guess they need to go on now, rather than later. Those were $25 or so. I want to replace the stem as the Ava which is on there has a bad reputation for failure. At a recent swap meet, I picked up a stem, bars and aero brakes for $10. I hope I can sand down the the stem to fit. Also hope my bar end shifters will fit the new bar. The original brakes are long gone, so there is no issue about swapping in the other brake levers.

Another $10 netted me a frame pump and seatpost mounted bag/bottle holder. There are no bottle cage mounts on this bike, so the bag was a good find. Also got a Fizik seat for $5.

Assuming I put all the new stuff on, I am at 85USD. This bike is my only drop bar bike and my favorite for pavement riding. It needs nothing else save for a way to add a 2nd water bottle for summer riding.

I hope to eventually do 100km in one ride on this, but its difficult to find the time at the moment.