So I've found this...
http://cgi.ebay.ca/3-70watt-Metal-Ha...3%3A1|294%3A50
and I'm considering bidding on them. What I would do is mod a halogen worklight and put it over my 10 gallon.
The question is, how limiting is this going to be in terms of what I can keep? I figure that I should have enough light for macros and LPS, maybe a clam, but I'm not sure... any thoughts?