Ideas, yes, good answers...
Old book p. 150:
Hull Damage: Each lost Hull point can be replaced with a Routine (6+) Mechanic check (1 hour, INT or EDU), consuming one ton of spare parts for every 10 Hull points repaired.
New Book, p. 159:
Hull Damage: Each lost Hull point can be replaced with a Routine (6+) Mechanic check (1 hour, INT or EDU), consuming one ton of spare parts.
Now... I did get to review the update prior to its release, and at least on the draft I received, neither of those things where there, and I left the comment, "Hull damage fell off…".
Clearly it was fixed, but it may have been fixed by not completely restoring the old text. I would like to believe that the hull damage sentence is still intended to end with "for every 10 Hull points repaired." Especially since one ton of brand new starship costs only Cr50000 and a ton of spare parts costs twice that amount, and critical damage repairs cost a small percentage of the cost of the component (drives, weapons, etc).
So officially, it's Cr100000 per ton of hull damage to fix it. Unofficially, see Traveller Rule Zero (p. 4).