I threw 5 together fairly quick using left over MDF. No casters but could be added very easily. Cost, virtually nil with the exception of paint.
Here they are getting ready for paint.
When not in use they get tucked into the upper door compartment under my stairs, and the poker table rolls into the lower door compartment.
The tables work very well though for what they are (scrap wood). I don't actually have any pics of them finished painted, but I will grab some for you and post.