Just had to do a grocery run today and wanted to confirm/update my earlier numbers that I reported from top of my head.
$12.99 (US) for roast beef, with corned beef and pastrami all the same. This is for Boar’s Head at my local Krogers. No other options that I saw for what it’s worth, but they could be other options outside the deli case. Turkey and Ham were $6.99 and 8.99 respectively. So yeah, about what I recalled.
By way of comparison a New York Strip was $11.99, and Rib eye was on sale for $7.77. So, going to continue to avoid getting roast beef for sandwiches. The few times I crave it, I get a roast and cook it myself - even if I lack the slicer to get the thin slices, I can make a ‘steakhouse’ style roast beef sandwich for less than half the cost of the deli option.
You can slice meat very thinly with a ceramic knife or mandolin. Especially if you freeze it for a few minutes. Good enough for me, but I’m sure a slicer would be a good investment if: you make your own meats, have a large family, hold many parties or eat sandwiches daily and have lofty standards.
My local Hannaford’s regularly sells Old Neighborhood Roast Beef at $9.99 a pound, Nature’s Promise Roast Beef for $11.99 a pound and Taste of Inspirations Italian Roast Beef for $13.99 a pound. Sometimes they put them on sale for a dollar less.
I went to my favorite taco truck for lunch yesterday, and they had a sign up saying something to the effect of due to a nationwide shortage of beef due to COVID19, they had to charge an extra $1.50 for carne asada versus their other meats. I don’t know if this is related to the OP’s observation or not, but I thought it was worth mentioning.