The whole choice beef tenderloin you get at Paulina and what you take home from Costco can't really be compared by the "as purchased" price.
At Paulina, you get a completely cleaned tenderloin roast. The chain, tail, any peripheral fat, silverskin, the blood inside the bag, and the bag have been removed. You now have 40 to 45% less weight than you started wih. The highly skilled butchers at Paulina will even wrap the roast in thinly sliced suet before tying it with butcher's twine. This costs money. Your 7lb. whole tenderloin now weighs 4.2 lbs (or less)! (That's before shrinkage. Roast that puppy at high temperature, and you'll lose another 16-18%! Slow roasting, only 7-9%.)
OK, switch to costco. You take home everything...the chain, tail, fat, silverskin, blood, plastic bag. Let's say just for argument's sake, that Costco's price is $12 per lb.
This is a nice event that kafein is catering, so he can't just roast the whole tender, right out of the bag, like the Holiday Inn does (not that there's anything wrong with that). He can't serve that fatty, gristly chain to upscale clients, so he trims it away. His clients want to see that same elegant slice of perfectly cleaned tenderloin on a cocktail roll that they get at The Four Seasons. His cost is now at least $20 a pound, up in the Paulina ballpark.
But he does have some tasty scraps for a couple of good meals at home. Beef tenderloin tips, tenderloin tail medallions, or he could even grind it for hamburgers or meatloaf. Only thing, those scraps cost him $12 a lb.
Kaffein might be able to take home a completely cleaned, oven ready tender for the same price. He now has no labor for the butchering, and heck, he doesn't even need to go out and buy twine! Paulina can sell those medallions from the tail for 9-10 a pound, and those tenderloin tips for the same. If he decides to do the butchering at home, he will have to deal with that waste.