The average 5 pound of BTMS is around $44. If a business were to make 100 ounces of conditioner bar base at 60% of the actual product being BTMS they would be using 60 ounces of BTMS. Theyd be using almost 5 pounds of BTMS spending about $40 just to make 60% of the product. If they sold the bars at 5 ounces each, they would end up only making 20 bars. Comparatively a business could make a deep conditoner using 10% btms making a 300 ounce batch of deep conditioner and still end up using a significantly less amount than if they made the conditioner bars even if the conditioner bars are made in a smaller amount.
I just dont think in the long run it would be cost efficient. Bottles arent an expense compared to BTMS especially considering the fact that around half to the majority of a conditioner is water. From my experience expenses are in this order: BTMS and conditioner emulsifiers, preservatives, oils and butters, labels, bottles, water in that order are what a businesses product making expenses are.
Now Im not saying that a business wouldnt do it, like DB MIGHT, as from what I can see, she charges a very fair (and to be honest low) amount for the quality ingredients that she uses. So maybe the large demand that she has would compensate for the expense? I dont know. But it would undoubtedly be expensive to produce. Cocoa butter isn't exactly cheap, but people use those to make bath melts, they MAY be able to use that as a main ingredient and less BTMS. Again, it'll be expensive but probably not as much. KBB might do it, since she uses pretty basic ingredients anyway.
Ive never fooled with the ph of my conditioners, for the most part that doesnt really matter to me, but I know that you may find better use with the lactic acid.
But I do think that you should try making your own, just because it's fairly simple and you can easily add whatever hair loving ingredients you like in the mixture without having to worry about emulsifying, separation, grit from unmelted conditioning flakes etc.