Yes, more than likely I would. I had Tome of Horrors 3.0 for a couple of years. Then I decided to thin down my collection a bit and I sold it. Big mistake. Fast forward to last Christmas when I finally picked up Wilderlands of High Fantasy and discovered all these references to Tome of Horrors. I downloaded the $10 pdf version of Tome of Horrors 3.5 not long after. It's much cheaper and I'm glad to have it, but...it's not a book.
Until I leap into 21st century and get a laptop computer it's not very convenient either. I had the idea of printing the entire thing out myself, but realizing the time and expense involved I decided against that as well. For now, I just print off the creatures I intend to use in a specific adventure or campaign. While that's handy, I'd still rather have a book I can reference anytime I like at (or away from) the table.