As an apples-n-oranges comparison - my 150 was in a similar state, having not flown for five years (and flown very little the previous ten). Then, in 2001 it received $10k of maintenance before I bought it.
Now, to be fair, that particular shop was known for its high prices - all defensible, no outright padding of the bill, but every nut, bolt, washer and cotter pin was accounted for and billed... along with the labor to install.
On the other hand, none of that bill was for engine work outside of an oil change, spark-plug cleaning and new air filter.
Sooo, in my random sample of one static plane, you can spend a lot of money getting the airframe airworthy and still not have made it forward of the firewall. Then again, I put 1000 hours on that engine before it needed an overhaul.
