My local Harbor Freight has Rotella T4 15w-40 for $21.99/gal and BlueDef for $14.99 for 2.5 gallons. An unlikely source but it's there.
Walmart def was 6.88 now 10 bucks a 2.5g cube. That escalated quickly.
My buddy has a semi and just had 1400 gallons delivered. He didn't even ask the price, but I know it was well over $6.00 a gallon. When he works delivering fertilizer he burns 105 gallons per day. He thinks it will be over $8 by summer. I just drove from CA to NC and it reminds you just how much is delivered by truck and train
I've cut way back on truck use and mine is pre DEF, debating on pulling the 5th wheel RV very far. Even filling up the CRV with regular is painful.
I don't see local business surviving long, the restaurants are about done for. No one can afford the drive to work around here! My local Walmart has oil and DEF usually, for now anyway.