Yup, until COVID subsides prices will reflect tight supplies, and the coming holidays will further exert pressure on pricing. Don't be afraid to try locally sourced USDA Choice packers or even flats. Do you have box stores handy? Costco, Sam's, Restaurant Depot or a decent butcher shop?
I always probe top to bottom, straight down.
3-4 degrees or 30 minutes.
I leave a tad more than 1/4" of fat over the top and try to remove as much of the hard knobby stuff between the point and flat. The loss is usually between 20 - 25% of total weight. A bathroom scale should work if you have one. Aaron Franklin has 1 or 2 YouTubes on brisket trimming. He likes to square up the sides and ends as he can use the trimming for sausage, staff meals, burgers, etc. Just try to keep the amount of fat even in thickness for even cooking.
!0 + years ago I wrapped with foil. Now I use a dbl layer of peach paper. 2-3 hrs is fine on the hold. Franklin claims 140 is the ideal slicing temp. I've never gotten that fussy about it.
Generally I put 1 probe diagonally into the center of the point, and another one diagonally into the center of the flat. Point temps tend to ride 3-5 o higher. Always go with the flat temp (along with probing for tender)