Basically, what could one do with a lot of money in the old American west? Buy a better gun? A faster horse? In the movies, it doesn't seem like money could really get you anything but things that a normal person could already afford.
Comstock miners boasted that they were the highest paid industrial workers in the 1860s and 1870s - making $4 per day (for an 8 hour shift). At six days a week, it would take one of those Western miners over 160 years to amass $200,000 - and that's assuming he could save everything he made with no expenses. There is no question that $200k could purchase a great deal. The owners of the mines could easily by worth more than that, but for a single score, $200k wouldn't be bad.
What could you do with it? - you could live like a king in a place like San Francisco - and if you were careful, you could do that for the rest of your life. Or you could buy a lot of property and businesses, and if you were careful, they would support you very well for the rest of your life. Many places offered many luxuries that you would want to purchase, so there were plenty of ways to spend your money.