Ha, you know what K-Mark, I have actually myself sat quietly in my room several times trying to average out words to page of the Lemony Snickett books to answer that very question! So using my poor math skills (saying 10 words per line, and 22 lines per page, times number of pages, so this is REALLY approximate): the first book comes to around 35 000 and the penultimate one around 77 000. So he's got a kinda JK Rowling thing with the writing increasing (though in miniature).
But I do think there is a website out there that someone once directed me to, where you can search a book and it tells you the number of pages. Anyone know where that is?