I picked up the same mixte recently for $15 as well. Thought I had a slam dunk. It needed clean up, tires, tubes, bar tape, saddle, cables, housings, all bearings serviced, chain, etc. You will need lever hoods. Anyway, I finally sold it, took a while, got $130 for it. After expenses, I really made minimal money on it. At least it was a net positive, but well below the $100 margin I was used to. Hopefully your market is better.
Now as an addition to the family fleet, its a no brainer.
This is how the market has changed. Used to be a nice mixte like this was $200 to $225. Sold one several years ago in that range.