Reverse Osmosis from Home Depot

I see that it's only rated for 10g / day of output. Depending on your tank size and frequency of water changes, that alone would make the model you linked to incredibly unappealing. There are definitely many more practical models in your price range from any number of retailers.
 
Check these guys out, they also have an ebay store that is $10 cheaper than their site prices too.

http://www.abundantflowwater.com/


I have to agree with Riiz. I have two RO units from these guys and both are great! They ship out next day and everything usually arrives in 4-5 days. Free shipping on most RO units through thier ebay store...

http://stores.ebay.com/Abundant-Flow-Water-Systems

And $169 for a RO/DI filter rated at 100GPD isnt shabby. Not to mention you get your choice of connectors (faucet adapter, undersink, or garden hose).
 
AquariaCentral.com