A museum director, in order to finance expensive new acquisitions, discreetly sold some paintings by major artists.
Conclusion (clearly)
The prices settle the issue of whether the museum director deserved criticism for secretly selling some works by major artists.
Intermediate Conclusion (since)
The prices demonstrate that the critics were right to say that these were first rate pieces and that the director should be condemned for selling them.
Evidence
Only a few months after the director secretly sold these paintings, they sold in an otherwise stagnant art market at 2-3 times the price the director sold them for.
Evaluate
The essence of this argument boils down to this connection:
pieces sold for 2-3 times → pieces were what director got for them first-rate
I don't really know how the bigger re-sale price indicates that the pieces were first-rate. After all, I might sell you a really crappy bike I have for $5. If a couple months later you sell that same bike to someone else for $10 or $15 (2-3 times as much), does that prove it's a first-rate bike?
No, it just proves that the original price you paid me was probably less than I could have gotten for it.
The author is interpreting a Curious Fact (why did the paintings re-sell at 2-3 times the value of what the director sold them for?) with one possible interpretation (these were first-rate pieces by major artists, thus highly coveted, thus commanding a high sales price even in a stagnant art market).
We would push back with alternative explanations, such as the one I just mentioned: - maybe they are inferior works, but the director just sold them for 1/2 to 1/3 of what she could have sold them for
- maybe they are inferior works, but the person buying them does not have a good grasp on what the right value of the work is, so they overpaid 2-3 times what they should have simply because they recognized the name of the major artist who painted it
Goal
Let's look for an answer that allows us to explain the higher re-sale price while still arguing the Anti-Conclusion, that these were not first-rate pieces and thus the museum director doesn't deserve condemnation.