The Barnes T-EZ, and presumably their other offerings, are worth the price of admission. IME MLs tend to put various bullets pretty closely together, so you need not use the spendy ones for practice (does anyone actually practice with their inlines?). I’d forgotten about the Bore Locs, but have so many others in hand I probably won’t ever get to them.
BTW, once you settle on one, keep your eyes peeled after the season ends for sales. I’ve picked up a number of bargains in the off season.