I have purchase CPS3205 from chines source available from Aliexpress, Ebay ,BengGood etc....
Cost is in the range of 50~60 USD include shipping (very low cost in compare to linear one)
this PSU provide 0-30V 0-5A switching power supply they work well but somewhat difficult to operate - have only one handle for current and voltage display is not very bright and they very lite weight (less then 1 KG) in compare to linear one I have, who weight above 10KG.
I can't be sure whether they fully isolated http://www.banggood.com/CPS-3205-0-32V-0-5A-Portable-Adjustable-DC-Power-Supply-110V220V-p-934530.html
All the best