$350 seems expensive. A long time ago I got a complete set of RO/DI gear with a tester, reservoir, and line pressure gauge for MAYBE $200 off eBay. This stuff is all made from the same parts more or less, so I would look around at other bundles.
A filter vendor hangs out here on HBT and his offerings seem popular, though I haven't needed to look closely. And that's another issue... depending on where you live you may not need to filter at all. I'd try to find water data for your town before buying anything.