Rockwool 2X6 (R-23) insulation batts. 1/2 bag (4 batts) of complete batts plus another 1/2+ bag of long/useful off-cuts.
HD sells a full bag of 8 batts for $89.15
https://www.homedepot.com/p/ROCKWOOL-R-23-Comfortbatt-5-1-2-in-x-15-in-x-47-in-Fire-Resistant-Stone-Wool-Insulation-Batt-39-8-sqft-1-Bag-RXCB551525/202531867
This half bag plus off-cut bag for just $25
Text or call 5 ONE 0 9 SIX 5 TWO 7 SIX 3