The poster says today only but it's been up for a couple of weeks now.
Basically, for $3 extra with any burrito you get a regular mexicrinkles, a can of drink and a dipping sauce. A meal is usually $4.50 or so extra and the sauce is about $1 I think.
Only seems to be available at Tea Tree Plaza, it's not at Marion or Rundle Place that I've seen.

 
    ![Add Reg Mexicrinkles, Chips, Drink & Dip for $3 with Any Burrito @ Salsas [Tea Tree Plaza, SA]](https://files.ozbargain.com.au/n/88/207388.jpg?h=3f23e142)

how much is a Burrito?