These may be too much if you are looking for 30v.. but i bought mine of ebay
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3059598209
Traco Power TSL480-155PX Industrial Power Supply
Input: 93-264VAC Auto-ranging, 50/60Hz
Output: 48-55VDC Adjustable, 480 Watts, 10A
they are $50.
i'm expecting them to arrive either friday or monday.