"cheaper" is a relative term because it means different things to different people and it's almost impossible (for me at least) to answer it in a forum like this because there are so many different variables. Someone who's qualified to purchase a property up to $150,000 might think it was cheaper to buy a condo in the suburbs versus a really small house in Denver. On the flip side, someone who's qualified to purchase a property up to $500,000 might think they could get more for their money getting out of the city. I will say this...Denver taxes are typically much "cheaper" than the surrounding areas (when based upon the same priced property), but that never seems to be the driving force behind a buyer's decision because there are other higher-priority factors for them.
If I were asked this question by a potential buyer, I would ask them to define what "cheaper" meant to them. Their answer to this question who provide immediate insight for me to determine what they're thinking and helps me adjust their expectations accordingly. At the end of the day and regardless of where they decide to live, my goal is always to find the BEST home, in the BEST neighborhood at the BEST price (within their price range based on criteria they've shared with me). I hope this helps.