I've found a lot of good stuff describing life and travel in the west, but haven't had much luck locating things like exact prices of goods and services, wages, or maps. I would love to find some maps of locales like Dodge City, if such a thing exists, but my google fu has so far failed me, and my local library doesn't have much. I asked in /r/history a week or so ago and never got a response.
If you're looking for maps, one of your best bets is Sanborn Fire Insurance maps. It looks like maps existed for Dodge City shortly after the period you're interested in. Sanborn Maps are not free, but your local library may have a subscription to an online database. Also, they were fire insurance maps so they were generally only of areas that were wealthy enough to worry about fire insurance, but they're still one of the best sources of (US city) historical maps we have.
1875 Montgomery Ward Catalogue Catalogues were the major way of purchasing items in the Old West. The local general store would generally have a collections of them you would place an order at your local store and then wait about 3 months. You can find other catalogues online if you look around.
At this point in time 1870 - 1875 wages were about 10 cents/hour for blue collar workers. It came out to about $1/day or $30/month.
I'm afraid I don't really have a great source for maps.