What's the lowest price steam has ever sold a game for?

www.enhancedsteam.com and you can see for any game.

However I think you may be actually asking:

"What is the lowest priced game that has ever been sold on Steam?"

In that case I am not exactly sure, but it would probably be one of the pricing bugs like Just Cause for 27 cents.

RE: "Free" comments. Is it technically a "sale" if no money changes hands. I will agree that it is a "transaction" of sorts, but "sale" or "Selling" usually involves some exchange of goods (barter) or money.

Free?

0,00€

I think Just Cause had dropped to about £00.07 in a price mistake and people had bought loads.

Portal (1) was given away for free at some point.

The lowest that I've seen that wasn't a pricing mistake was P.B. Winterbottom for $0.49 during a Winter Sale. Think it was a year and a half ago. Lowest I've seen otherwise was Just Cause 1 for $0.27.

http://i.imgur.com/dI4VTzx.png

This i think

CS: GO was $0.14 for half a minute

Just cause was like 16 cents right?

Fortix was on sale for $0.24 during Holiday Sale

This was pretty low, but you couldn't actually buy it.

Portal 1 were free for one weekend. 0.00$ :)

I would have to say FS(Faerie Solitaire), because it got given away twice. One was on SG, while the other was on a site known as Epic Solitaire.