Thanks for bringing this to our attention. The cookie fix is now included in the utag.js version 4.37 template. The template update is set to release tonight and be available on Feb 20, 2015.
This is a great catch. Previous utag.js versions would treat the "$" as a delimiter in the utag_main cookie. This resulted in a messed-up cookie. Combine that with the comma in "$50,000" and you would see the strange cookie created. (Note that cookies set outside of utag_main were not impacted as they would not use the "$" as a delimiter for name/value pairs.)
We've also added logic to clean up cookies in a bad state (this will remove the comma in previous cookies.)