DIY ATO or are the kits worth it?

I've been searching ATO setups and have seen prices from $30 -$300. I know I can build one with a bucket, a switch and a pump but that'd cost $30 alone! Are these "kits" worth the price? Or is DIY the way to go? The longer I'm in this the prices on reef equipment are becoming more justified in regards to reliability.

What's the best kit under $100?



FYI... If it matters I'm evaporating 1-1.5 gpd.