Hi, Wing117!
Well, I can say that you're not missing anything in terms of sticker shock for housing. There are a variety of reasons for this, from frequently being known on "Best Places to Live" lists (as diverse as Outside magazine and US News and World report, who are each looking at different factors), to a good economy (not much of a "bust" in 2008/2009 compared with many other places), as well as other regional things-natural disasters in CO Springs and Northern CO in 2012 and 2013 wiped out a lot of houses and put pressure on the market in those areas.
I would definitely consider renting first. There are some signs that the real estate market is softening a little, though the underlying support is there for a flattening out of prices rather than a steep drop. There is low unemployment and fairly diverse economy but wages have not kept up with housing costs so that is why I think it will flatten. Housing is less expensive in 1) smaller towns/cities and 2) either east or west of the Front Range. The jobs are fewer for condition 1 and the commute worse for condition 2. Also keep in mind that there are good historical reasons people tend to cluster at basically the base of the mountains: wildfire risk to the west and hail alley to the east.
All that said, it really is absolutely stunning here (there's a reason housing is rather expensive!). It's difficult to put down a list of places to see, because there are so many. I would recommend checking out the places you may want to live and the places you may want to visit given whatever activities you're into. If you love water-related things like fishing or paddleboarding, you may want to find places closer to a reservoir. If you love downhill skiing, you may want to be on the west side of Denver for quick access to I-70. If you want good hiking, you can find that anywhere-you just adjust your altitude per the season/conditions you want. The only time of year that's slightly meh, in my opinion, is about Halloween until about the New Year-it's fairly dry but cold, and everything is brown but not covered in snow (usually) down low. You won't have to go too far to find snow, however, but the skiing or snowshoeing is better usually starting in January. Earlier in fall is pretty-it's not the colors you get back east but the weather is usually dry and sunny and often a pleasant temperature (mid-60s give or take).
CO springs to Longmont is probably about 2-2.5 hours or so drive, so you can easily check out each area you mentioned even if you only have 4 or 5 days. Try to spend at least a whole day in each, getting a bit of a sense of the place. If possible, find a local brewery or coffeehouse or café and ask the people there about the area. Also, you might check surrounding smaller cities and see what the housing/commute is like. CO Springs is more conservative, with a large military presence, Denver has all the amenities and traffic of a major city but if you need/want to travel a fair bit it may be worth being closer to the airport than other places, Longmont is a much smaller city (~100K) and may have reasonable housing. I would imagine there would be job opportunities for IT in any of these locations.