I am sure that other markets with a real butcher counter can do this, but I don't necessarily have those around me (Krogers not so much, Papa Joe's in Birmingham doesn't cut their own on site, etc.) and didn't feel like heading to Eastern Market in 5 degree F temps today, but wanted to make beef pho broth (using Steamy Kitchen recipe, next time will do the Serious Eats long time and then 1 hour versions).
I called Royal Oak Holiday Market, where I like the meat counter but have not seen soup bones on display, to ask if they had bones and a very helpful young woman at the meat counter answered and said "yes, just ask at the counter." They did have them for around $2 something per pound, and the young woman who helped me at the counter (I think the same) picked knuckle and leg bones for me per the recipe. They worked very well for the beef broth.
Moral of the story is to call if you need something - stores with full service counters and customer service may well have the ugly (oogly) bits behind the counter, etc. but can help you. Heck, they may have caul fats, suet and other oddities back there too, don't know if you don't ask. Hillers may do this too, I just don't live close enough to one. Also - call before you go and save time and gas.