Many juice makers contract a lab to produce their juice. A well respected, but relativly small juice maker was on VU Live taking questions. His juice is produced in a large lab, his cost per bottle, labeled is $2 per bottle if I remember correctly.
On the surface, it would seem that the profits are huge, but it comes down to scale. The cost of having to pick up 500 bottles per batch, pay the fees for his online payment processing, The rent on his warehouse, the time it takes to process and cross check every order, the cost of mailing and cost of replacing damaged or lost orders leaves him with a profit that almost does not make it worth doing He also mentioned that it takes him months to nail down a flavor worth selling, time that he is not directly paid for.
If I recall, he needed $8 a bottle to break even.. He was switching to selling to large wholesale only, as much of his time and overhead are reduced, but the consumer will see no reduction in price, as the wholesaler obviously needs to make money as well.
The same fellow is incredibly supportive of DIY for personal use, and believes that the market will stabilize, and that juice that is exceptional will maintain its place in the market, and much of the junk juice will fail as regulation and DIY fill the vacume, He said that the juice he makes personaly for himself costs less than $0.60 per bottle.
I found him very candid and credible. I'm not in the vape or juice biz, but in any business there are costs the public does not see or consider.
The shop mentioned above, should probably consider outsourcing their juice operation, and wait fot the juice sales to justify the expense of an in house lab. Even if they only commision small batches at a time, if they are selling it direct for a reasonable price per bottle, with a cost of 2-3$ per bottle, it might keep them afloat.