Where are you looking? I just looked on Seat Geek yesterday and the only shows that are insanely expensive are her first show and then the first weekend she's in it. Everything I looked at in later Sept and Oct (just pulled up about a dozen dates, a mix of week day and weekend shows) did not look well sold at all and were actually on the lower end for full price Broadway tickets these days. There were probably hundreds of tickets between $89-$179 for each show I looked at including a bunch of orchestra Tix for $89.

Premium seats were generally in the $200 range - except for her first show and that first weekend and a couple of random resellers. Again, that's very much on the lower end these days. Compare with Music Man where premium seats were going for $700.

Unfortunately Broadway prices are just that high now. But aside from that first week or so it does not look like Funny Girl is selling that well for now in terms of pre-sale. We'll see once reviews come in for Lea. That could change things.