Is this Legal?

Above is everything I got at CVS today for a grand total of $6.62. I also earned $10 in ECBs to spend on my next visit. The manager was impressed that I keep earning so many extra care bucks...apparently he hasn't figured out the system yet! I'm stocking up for vacation this week:

2 bags peanut M&Ms - 2/$5
1 bottle Dawn dish detergent - $.99 and used $.25 coupon
1 pad of writing paper - $1
6 12-packs of Coke products $3.25/each, plus buy 4 get 1 free (this deal wasn't supposed to kick in until tomorrow, but it was in the computers today!)

used $5/$30 coupon and $11.50 in ECBs
Paid $6.62 out-of-pocket