The Register Reward deal I mentioned actually works on the regular 3 Musketeers Bars, not just the Truffle Crisp: $1 RR wyb 3 or $1.50 RR wyb 4.
You can sweeten this deal further because Walgreens currently has an in ad coupon for Mars candy bars (3 Musketeers bars are a Mars candy product) which will make each bar just $0.49! And the regular 3 Musketeers Bars are the correct size for the in ad coupon!
Buy four 3 Musketeers Bars
Use the Mars candy bar in ad coupon which will make each bar $0.49
Get back a $1.50 RR
Final cost: $0.46 total ($0.15 each)