Hey James, welcome to BaliStartupers!
Employing an expat in Indonesia wihtout a visa is illegal and can be a bit risky for the employee as well as you.
The price of the KITAS is around USD2000
Salaries depend on the job he/she has to do obviously but I don’t know anyone making less than USD1500/month
Now there is an alternative to that! You can use interns for free or almost.
You need a PT or a PMA to be able to do that though.
They would be on a Social visa. 2,2 millions Rp if you have an agent do it for you (recommended)
Interns can’t officially be paid in Indonesia.