FYI, if you check his eBay store, in addition to the 10-plate models for $45, he's got 15-plate models for $58 and 20-plate for $69 - plus even bigger models if you've got the $$.
Now I'm trying to find specs on the existing homebrew plate chillers (shirron, therminator) so I can try to compare them apples-to-apples in terms of surface area and flow rate. If the 15- or 20-plate models can compare favorably I might very well be sold on the idea.
From:
http://www.hbd.org/hbd/archive/4912.html
According the the above site the therminator has 6.5sq ft total surface area
vs Shirron's 2.4 sq ft.
The ebay chiller claims 0.14 sq ft per plate, so the 20 plate model would have about 2.8 sq ft, a bit more than the shirron. But if this is all true, then the 10- and 15-plate models would probably prove to be too weak... And comparing cost:
The S20 model is $69 plus about $14 shipping (at least for me), so a total of $83.
At NB, the shirron is $85 plus $8 shipping, so a total of $93.
To me, a $10 savings doesn't seem that great considering that A) The shirron has a decent reputation and is made for brewing, whereas the ebay one is an unknown, and B) the shirron has 1/2" NPT and garden hose fittings, the ebay one has 3/4" NPT fittings, which don't seem as ideal.
On the other hand, with twice the plates but half the length, the ebay one should offer much lower flow resistance than the shirron, depending on plate spacing I guess.