I like to get my hands on the cheapest edition I can in the best condition at that price. If the words in the book are the same as a more expensive one, I’m getting a better value, in my opinion. Then if it’s a story that becomes really important to me I might consider upgrading to a “nicer” or collectors version, and keep the old ones as lender books.
If I had no dependents I’d buy more expensive, I prefer hard covers or books I can rebind. Depending on the series I’d be willing to shell out 60-100 a book. New reads I get now are always from book sales or discount stores. Can’t exactly drop 600 bucks on a series and keep up with my kids, wife and our pets