I don't tend to buy them, but it's not all about the price. When paper was the norm, I tended to buy paper backs vs hard backs. So I'm just generally willing to wait until they're no longer 'the latest thing'. With eBooks, it's EASIER for me to borrow from the library -- way more convenient -- so I put a hold on 'em as soon as they're listed and read 'em when my turn comes.
If it's a book I really want to read, I go to the e-library to check it out. Sometimes the wait list is long but that's okay. I'd rather wait to read it than pay over $2.99 for it. If all else fails, I still visit the brick and mortar library from time to time.