I installed the 3 stage whole home filter system from Express. (
Standard 3 Stage Whole House Water Filter | Express Water). It's only $399, and is easy to install. The specs are the same (or better) than the Nova system, and there is a pressure gauge for each filter - not just one for the whole system. This gives you the option to replace each filter as it is actually needed as opposed to replacing all 3 at the same time regardless of whether all 3 need it or not.
Installation took me about an hour, and I spent ~$25 at Lowes for plumbing, disconnects, and PVC glue.
It works fantastic - the water tastes better than any of the bottled water we have had.