The last set I bought was $400 delivered and installed.  

That's not where you get the best price for either the water heater or the installation cost.  

Dark floors, white walls, rectangular tile, they're proven winners.  

Just have the carpets cleaned.I have never installed carpet in the living areas of my rentals.

Did you find a way or place to buy them and installed more cheaply?

Get a granite guy in and install a nice mantle.  

With new bathroom, widening one bathroom door, upgrading a toilet in master, granite on kitchen island (had ugly tile), hardwood flooring, upgrading lighting in dining and kitchen to can LED lights and paint, we spent about $19K in upgrades.

As a mortgage banker having dealt with a whole number of credit repair companies, all 3 CRAs as well as other credit restoration/support companies, I can tell you that you're best bet is to have the following:1 - 2 installment loans which would include a mortgage, car loan, car insurance, student loans, etc.  3, yes 3 revolving credit lines (so 3 credit cards)carrying a 20% - yes, yikes but I've been told by many, many sources this is correctKeep in mind that the credit score you pull from creditkarma and freecreditreport.com will NOT be the same scores you get when a lender pulls your credit for mortgage purposes. 

For those that don't know it is an alarm system you can install yourself.  

We had tenants who had a situation that made them pay the rent in installments for a short time but that is working with someone with an issue.