By entire event do you also include the 40,000 -security force? How much does the government take on? Every cent cannot be covered by donors.
You are right. The op is wrong.
The biggest costs are incurred in security, paid for by the taxpayers.
The $40m figure for the Bush Inauguration does not include security costs, which were about $100m.
The Obama figure of app $150m does include security costs.
Media matters has more on this subject.