Unfortunately its only for a limited time. After that you can only get it for smoked ham, tuna, and a few others. Also the Subway Feast and philly cheesesteak are not included. Another thing I forgot to add was that participation may vary. So if the restaurant is being screwed heavily by taxes and stuff, then forget it.
Don’t know why the simple ones like turkey etc. aren’t included in the regular $5 list. I can’t imagine it being so expensive....I bet it’s because they sell too many of the simple ones and try to drive up sales on the elaborate sandwiches.