Wow, that blows my mind. I know Vail is a very nice area but those prices are crazy compared to what I am used to. Anyway I would check into the county and see what the actual land is valued at. A 1974 mobile home is not worth too much. I can see by the pictures that a lot of stuff in that place has been redone from what it used to be which is a good thing. The roof is also a good benefit. I see it has a swamp cooler on top which I would get rid of. It must have some sort of addition on it or the sqft is off on the listing. For that listing price the land would have to be worth at least 150-160K as the home is not worth much. Newer single wide homes can be had for $10-25K depending on year and condition. Insurance on that year of a mobile home will also be an issue and that I would call around and ask about first. From an insurance standpoint I would think there might be limits on how much they would even insure. Wiring in that old of a mobile home could be made out of aluminium as well instead of copper which is better.
I know that you might be looking to jump in to get started but make sure you check everything, run the numbers and make sure it all makes sense first.
Just some thought to think about.