It depends a little on what you are planning on using them for. If it's just to have and play through for enjoyment/education, or to follow along to recordings then any of the cheaper editions is good value. In the standard repertoire, faults are minimal and you really don't need a three page editorial discussion on whether a note should be sharp or natural. Schirmer is generally fine for that, as are Dover and Presser. Alfred's is, in my experience, a bit of a mixed bag, and Kalmus should be a last resort unless you get one of the older red covered ones.
If you are going to study a piece for an exam or an audition, it may be a worthwhile investment to upgrade at that point to one of the pricier editions.
A word of caution about "Urtext" - at the pricier end it's a word you'll see bandied about often. In the best editions, it means that all editorial decisions are noted, and any editorial markings are distinguishable. Sometimes it's useful, most of the time it's really not. And quite often it is used without actually meaning anything. I find a cheaper edition, with a little research on IMSLP and a judicious use of the pen, will work for pretty much anything. That said, I have editions by pretty much every possible publisher in my collection.
Topic: Having trouble deciding what new books to buy