.... I think you were looking at the wrong power supply. The one I was referring you to was the second one down on this page:
http://www.hosfelt.com/en-us/dept_16.html
Its a 3amp'er and 5-3/8" x 3-5/16" x 2-1/2" in size... is it likely to be a linear supply?
$20 is still pretty reasonable if it looks promising.
Jon,
While I too, was impressed by how well hung that adapter is, the critical point in
5-3/8" x 3-5/16" x 2-1/2"
Input: 100-250 VAC, 47-63 Hz,is the 100-250VAC.
if it were 120/240 it would indicate that it has a transformer whose primary can be switched from parallel to series, indicating, typically a linear supply. But the fact that it can cope with any AC voltage from 100-250V, clearly indicates its a switcher having no input transformer. Honest.
See, snarky, yet edumicational

But to hedge your bets, I would encourage you to buy them all
EDIT- the fact that the exact same adapter is found under the listing for switchers (5th one down), confirms what I said above -
http://www.hosfelt.com/index.html?target=dept_223.html&lang=en-usRegardless, when you first mentioned this adapter, I should have explained WHY I reasoned it was a switcher, rather that toss off 'its a switcher'. A major purpose of this forum is to share information, not facts, and your follow up questions were a direct result of my failure to do that.
Sorry 'bout that.