Dies aren't cheap, just on a performance vs cost basis the 45-120 is more economical and will out perform it at equal pressure due to the much larger case capacity, 3-die sets are around $50, can be reamed by hand with a rented reamer, on the other hand, it's something different and Elk Ridge rents the 450-348 Ackly reamer. Kind of a toss up on the brass vs die cost tho, 348 Win brass is $40 for 50, 45-120 is over double that, can't beat the shock and awe of the big 45-120 round tho!
Tim
NOTE: I just checked Cabela's, they have Norma 45 Basic brass on sale, the stuff I got from them was 3¼", but Norma makes some 45 Basic brass that's shorter, you'd have to call to check.