Illinois does not have legal CC; so no, I never spent the money on something I can't legally use where it would be useful. I hope Illinois has good CC by summer (best possible scenario), in that case - shopping spree.
I train where time and budget allows. The range I go to is a private club, one fee for year long use. No hourly charges and more than enough room to practice any firearm I want, at any distance up to 300yds, for as long as I want. So I never feel rushed during practice to save money.
Legally, schmegally. You've got the pistol for repelling boarders, right? You, sir, need a holster and at least a single mag carrier. Ignoring the capacity issue of whatever your defensive pistol might be, it's a malfunction clearing issue. This is training.
Does your private range allow drawing from the holster? Close range target practice shooting from hip-index position (i.e. unsighted shots)? Rapid magazine changes? Movement while shooting (getting off the X, etc)?
The only public range that allows drawing from holster here in the PHX area is Ben Avery. The indoor ranges I've been to have differing rules... some never allow it, some allow it if you've taken classes at their facility and are on computerized record as having cleared that skill. Mostly, if you want to practice something more than bump on a log public range bench shooting, you have to join some sort of competitive league or keep taking expensive classes, or go out into the desert where there is no RSO and EMS response is very slow if something does happen to go wrong.
Get into some sort of IPSC/IDPA/steel/ICORE handgun shooting. There's a whole new world to shooting that will wake you up to the value of multiple magazines, and just how valuable 1 more round of ammunition can be, how little time 18rds in a handgun can buy you in a gunfight, or magazine duration with 10rd Clintonized mags versus 17rd natural mags, and so on.
Last range trip I put my 1911 mag on the table and it somehow got mixed in with my range mags. My buddy was all when I told him that cost $1.20 a round....
DT, having spare mags prevents expensive mistakes like this. Jamis and I are hardly the only two people who have done this before. Carry mags for carry ammo, practice mags for practice ammo and regular dropping on the floor and stepping on and filling with desert sand from run-n-gun stuff. Then another spare mag or two in the truck, another spare mag or two in the nightstand, and another spare mag or two NIB in any of the carry mags gets damaged.