I have a Mondia that had that kind of bubbled rust on the top tube from years of hard racing. The painter (Ed Litton) cleaned the metal bare, used some filler for the pits, and resprayed. Looks and rides like new. All the work on the buyer's part would be working to earn the dough for the chosen restorer, and then waiting for it to be finished.

I don't think that frame is toast, and OFG is right - about $1K give or take, and you have a nice restoration on the frame set. Even if the top tube was done, it ain't a huge deal to replace it before restoring. Aforementioned Mondia had a cracked head tube, and it was replaced during the refinishing process. Cost me an extra $70.

Not too much more cheddar, if you have the cheese in your pantry to begin with.......

Hell - I'd be tempted, if it were my size.