RottedOak, you are aware that the builders jack up the prices of the upgrades, right? Why would you prefer to pay someone 4 times the cost to paint a room than what it would cost to hire someone out/do it yourself? I think by far the better investment would be to have the mello roos paid off and put that money towards doing the upgrades yourself (or contracting them out). $5K a year over 30 years is a much better value than having your rooms painted and new floors.
