So if I understand your example. I buy a $50M asset on the supposed hope that it goes up in value at which point I then donate it to the museum at an inflated

So if I understand your example. I buy a $50M asset on the supposed hope that it goes up in value at which point I then donate it to the museum at an inflated value. 50% gain seems like a fair bit in a short period but I'll use it for your sake. So 75M$ tax write off. Now assuming that I am in an expensive tax jurisdiction and I can write this against short term cap gains - 40% - thats $30M in a tax benefit. TL;DR. Put $50M capital to work to get a $30M tax write off in the future ASSUMING significant gains. During that time you get to own an expensive piece of art. So you get the artwork for a net COST of $20M ($50M purchase - $30M tax benefit). It doesnt make sense purely on economics of the example - unless significantly more capital appreciation in the asset, other reasoning for pursuing it or other tax benefits in the country.