Go with your gut. That is a lot to invest in a job that is a maybe and sales are ALWAYS a maybe.
My husband used to wait tables and he would ask me for $20 so he could "give change" to customers. I would always ask why the restaurant didn't give him change and he would say, "they don't have that kind of cash on hand at the start of the night." I never gave it to him. I told him (the two times he asked,) that we didn't have the money either.
Later found out on both those nights he took 20$ from the ATM and probably bought drugs.
So, I may be the wrong person to ask, but I'm always wary of things for jobs costing so much. Sounds like the wrong kind of job to me if you need a lot of money to get started in it.