No that's a perfectly reasonable request. If I had someone ask me that, I'd have no issue as long as I were allowed to come with. As far as the owner selling the car before you had a chance to see it, well that's probably just a coincidence. If I got an offer and I didn't have any verbal agreement on price with someone else, I'd sell it.
2009.5 SBM GT: Lots of show with some go.
The garage queen.
2008 IOM GT: Some go, working on the show.
The daily driver.
2004 Blazer Xtreme: Lots of go.
Sold and will be missed.