Mmm, but there's get out of your chair, and there's spend $2,500 on a trip to a museum! I don't think you should feel bad for being unable to do the latter. I think you're mistaken if you think many parents would do it. (I wouldn't, although I am so fortunate as to have the ability to do it if I chose - there are just too many other things that money would buy, like half a term's schooling. I have spent ~250 UK pounds on taking DS to London to see some museums, but that's about as much as I'd pay for an educational trip unless it was so stunning to all of us that we could decide to make it the annual family holiday!)
Maybe if you tell us which museum it is and why he's interested, we can help brainstorm other things he can do to further his interest that aren't just reading books? Fairly generic suggestions might include writing to the research scientists who work at the museum with any questions he has, and searching for which universities have people studying those topics, especially to see if there are any nearby.
