The argument I always come up with is that you use the same fundamentals for shooting a big bore pistol as a small bore, so why not spend 9 bucks for 550 rounds of ammo, rather than 15-30 dollars for 50 rounds? I'm in the same boat in that my wife hunted as she grew up, and used a .270 on Michigan deer, but I'm getting her started with pistols. She shot my dad's single six, and my mkII pistol as well as a mod. 66 with .38specials in it, and a glock 22, and decided she likes revolvers. So I picked her up a ss 5.5" single six. I figure that will give her her own pistol, and keep her interest when she knows that she can "whip" me with her gun. I also got a gp100 for her to use for deer if she gets good with it, and have every intention of giving it to her. You don't become perfect at free throws overnight, or run a 4.4 40 in a week, so why should you go straight for the end goal right off the bat? It's just going to frustrate the heck out of them, and prove that you need to work up to the point that you are proficient.
~~~Amos