How long will the $3000 tempering machine last (years)?(a)
How much will you need to spend in repairs & maintenance of the machine? Base cost + repairs = Machine Cost (b).
How many hours/month do you spend making chocolates? How many chocolates are produced? (c) Reduce those numbers to 70% - 80% because you're going to get sick, or want to go on vacation.
I'm not a chocolatier, so I have no idea, but I did work in business. Let's say
(a) is 10 years
(b) $6000
Then you'll need to recover equipment expense of $600 in retail sales per year.
Then (c), e.g. 100 x 12 (annualized) x .7 (efficiency) = 840 chocolates
Then 840 chocolates need to pay for raw materials PLUS $1.40 each chocolate for use of the tempering machine.
P.S. If someone wants to PM me with more realistic numbers here, I can update these figures.