The finish would probably be the area of most variation..

The only reason you have a variation in your set is because the square feet are different amongst units.

Its tough to exactly say but its as simple as people not being able to afford higher payments which would naturally pull housing prices down slightly.Personally, I firmly believe that there should be a greater variation in the interest rate a person receives based on their current financial situation, the LTV the loan is written at, and their credit history.

Is is it not weird that the variation in down payment could be 10% at one, and 25% at another.

Since you're not sure what the name of the color of the original paint was, you're also not certain of the brand of paint and there can be variations amongst the brands even with the same "names" of colors.Most bathrooms aren't very large. 

You're asking how to find the investors in your area who are actively buying properties.So...the answer to #1 is simply to have your realtor pull a report from the MLS of all the recent Cash Sales and see what areas are hot with investors.For #2...Craigslist ads for variations of "We buy houses"..."

I like a variation of @Elizabeth C.'

I'm really struggling with the variations I'm seeing in price, though.

I'm seeing quite a bit of variation or no numbers at all and want a realistic estimate.  

Jared, there are state specific contracts, actually many variations of each, for example you may have a standard contract for single family homes, one for duplexes one for multiple units, commercial properties, mobile home, as-is, etc etc etc...then you have various addendums to address specific situations, such as pre 1978 lead paint disclosures, short sale, backup contract, etc etc etc.usually the actual contract you will need is dictated by the nature of the home, the seller, and whatever contingency you may impose.