I actually started out doing the same thing many years ago, but then switched to collecting whatever denomination I could either afford or, in many cases, one that struck my fancy. The majority of my collection still is obsolete Las Vegas $5 chips, but I do have a bunch of other denominations -- including a 5 cent La Rue chip that I just picked up at the convention. Although, I did get a couple of nice $5 chips as well...
Steve Bedo