If you search on eBay there are cheap ones for 10-50 dollars, if that's cheap/expensive enough for you. If you are aiming to buy one in person and not online, Staples is a good place to start the search, just remember, price can affect its quality a lot.
the internet
You can replace your chalkboard with a marker board at any business supply retail store. Or you can order on line at Amazon or any e-retail stores that sell business supplies.
dont they suck
A cheap label marker with a large container for the labels aren't that expensive. Mostly Target, Amazon or Walmart will have them on the shelves. However, if you want a good quality one that will last longer, I'd suggest Staples.
A person can buy used items for cheap on ebay. Amazon is also another company where a person can buy items for cheap. The Salvation Army is another place as well.
the home depot
Check online and see if there are any deals on them.
I'd say you could easily make one with a piece of poster board or cardboard and a marker
walmart is a good place to buy a cruiser board but their fake boards
anywhere if theirs zumiez or krudco stores any where or you could go to a toystore and buy a cheap board
Any office supply store like Office Depot or Office Max.
A person can buy a cheap Volkswagon GTI at a car dealership that offers a used one or a deal with it. Examples of a car dealership are Edmunds, Autodealer, and Koons.