It's certainly valuable to me given the price of loaded 10mm ammo. The guys are probably simply asking out of courtesy to make sure that you're not keeping it yourself. As has been mentioned, most 10mm shooters are also handloaders due to price, availability, and selection of factory ammo.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar