for the standard calc/alk/mag you have either 2(3)-part solution (Randy's formula, look at BRS), or calcium reactor, any pre-made bottled stuff is going to end up being prohibitively expensive on a large tank.
If you're talking about the other stuff like amino acids,etc, then yeah... it's going to get pricey with a large tank period since there is no cheap alternatives... other than not doing them.
I personally have never used anything other than C/A/M on a tank, and relied on water changes for those "trace elements", however after watching 40 weeks of BRS's "52 weeks for a reef tank series" their dosing episode did get me intrigued with the KZ line of products... although that seems like a major commitment