Is this house a deal? How do I find out?

[James Ross]

There is a Colorado Springs property I would like to run by more experienced investors (I have just started learning). There is a house in Colorado Springs that has been on the market since November, which is a very long time in this market. They have dropped the price a couple of times. The house is 4 bed, 3 bath, 2500 square feet, 2.5 acre lot on a cul de sac, and is just outside the city limits. It has a few problems that I know of, and possibly others as it was built by the first owner in 1963. The garage was turned into a rec room and the basement has had problems with flooding. It is listed at $500,000. I don't have direct comps, but other houses in the area, updated ones, have sold for closer to $700,000. What is the best way to determine if this is a deal or would require too much to fix up to be worth it? Or would a buy and hold be better (my personal preference, if the deal is right)? Another catch is this is outside what I can afford a monthly payment on myself, but I know some people who could possibly go in with me. I am very new and don't know how to go about finding these things out so any help would be very much appreciated.