Not exactly ‘expensive’ but ....
All summer long I’ve been going to my butcher and getting a full tenderloin, untrimmed.
You can get em at Costco for about $80-120 depending on the size.
But I got me a HUGE cutting board and a sharp as fuck knife and I learned how to trim it proper.
Out of $100 tenderloin I got
10 x 5 oz filet mignon
And then with the rest I made what amounted to 15 servings of steak fried rice. Huge amount.
AND
Still has enough trimmed meat (chateaubriand part of the tenderloin) to make carne Asada tacos for 4 people.
I pitched the rest of the silver skin and fat but I hear you can make stock or burgers with it...haven’t tried that.
My kids eat like motherfuckers and so We need to keep that fridge full of healthy stuff.