Most varieties of Special K are 3 for $5 this week at Shoprite--half price.
I used a $1 off 3 paper coupon from a couple of weeks ago. Paid $4 for three original. Got back $1.80 + $0.50 for the EMB, which I had forgotten about.
Total was $1.70 for all three boxes.
You could get them for less depending on which variety you choose since the Ibotta offer amounts vary.