My city water isn't fluoridated but it is really crappy.
You can get RO filters WAY cheaper than $300 (well under $100), but it might be difficult to hook it up seamlessly to your sink without doing major modifications.
Here's the problem with RO: It gets EVERYTHING out of the water!! You WANT minerals and such in your water just like it comes from mountain streams and wells.
What i recommend is an inexpensive PPM (parts per million) water meter. Typical tap water will be anywhere from 300-500 ppm. About 250-300 is natural minerals, then the rest is chlorine, fluoride, probably some metallics or whatever else the water picks up on the way to your tap.
Then you will RO the water and you should have between water that is 5-35 ppm. The problem with this water is that it will WANT to pickup minerals and such, and thus as you drink it, it will LEECH important minerals and nutrients from your body!!
So what I do is I take a 5 gallon jug of the RO water with everything stripped out and I add the minerals I want back in using Concentrace:
http://www.traceminerals.com/product...ionic-minerals
I use the PPM meter to get it back up to around 300ppm.
Then you can take your 5 gallon jug and put it on your typical 5 gallon jug water dispenser. Use that water for drinking and cooking.