I had to come up with some price signs for the upcoming outdoor Farmer's Market I plan on attending at the beginning of June.
I had a couple Ikea picture frames laying around at home.  Then I found a white one at the thrift store for 25 cents!  Score.  Although brand new, they're only $1 anyway, but at least it saved me a trip to Ikea.  I also had some wooden coin things that a neighbour-boy was selling last summer.  I knew they'd come in handy at some point. 
Here's how you turn them into display signs.
Each frame has two hard plastic sleeves that you sandwich a picture in between.  I suppose you could make a price sign and put that in there, but I wanted little chalkboards. 
We only need one of the plastic pieces for each frame.  Like my fancy painting set-up?  I used little plastic medicine cups for drying.
Two coats:
Here's the fun part.... Placing them in the picture frame:
I have little holes drilled into the wood pieces as an option to hang the them, but I may end up duct-taping them to what I need. We'll see. There you have it, a low-cost price signage solution.