I've rented from Christy's Sports twice and it's not too bad if you only rent skis. $30 something per day after taxes. DEFINITELY rent in Denver. Prices at the Breckenridge stores are way more ($28.76 vs $43.96). Select the demo skis only option and they have a huge rotating list of skis on a chalk board to pick from. I got the candide 3.0's when I rented both in Denver and SLC. When you get there, they may try to just give you a pair cuz most folks they rent to have no clue what a ski even is, but take your time and look over the board and pick what ski and length you really want to ski on.
The stores vary in their selection and inventory though, so what the Denver stores may have might have, the Breckenridge stores may have already rented out.