I just looked at a typical billing rate for TMS and I am absolutely appalled that with your prediction of 45 treatments per week leaves you with a pay expectation of $20/hour. Stop telling us what your overhead is. Stop trying to compare your anticipated income to what psychiatrists typically make. Either pay a nurse the hourly wages that a nurse should make, offer benefits, and give a competitive vacation package. Would you ever go into practice with a physician and offer them half what they should make? If you WANT a nurse, PAY for a nurse. You CAN afford it.
(I mean, seriously, the last commenter here is running a TMS program. In my observation, programs offering only one type of treatment (and hiring "coordinators", no less) exist because they're profitable.)
Also, for the love of god, don't hire a new grad nurse. This would be career suicide for a desperate new grad who would accept any offer thrown at them just to start working, especially if they continue to work for you for a long time.
God, I'm going to have this thread rattling in my brain for awhile now. Just when we've been working so hard toward better respect between different types of healthcare licenses, stuff like this still happens.