There are a lot of variables here....

First, does the DoM play the organ as well? If so, the role of organist is probably part of their salary. If not, your location will matter as to what the organist is paid. If you are in a small, rural area, you're probably paying someone who plays as a hobby...so $50-75 a service. Otherwise, you're probably looking at around $100-$150 per service. If you are paying one person to play five Masses, you might just want to work out some sort of salary. I generally pay someone per "service"...not liturgical service, but service rendered....that means rehearsal too...how you arrange that will be totally dependent on your location and your organist. Again, if you've got a midweek rehearsal as well as five services that someone is playing for, it's going to be beneficial to the parish to work up a salary.

As for cantors, I rarely think a cantor has to be a classically trained singer. Rather, someone with a pleasant voice usually does fine. You will probably be able to find a volunteer that would be able to accomplish the task very well.

Your library costs will depend on what type of music you sing. Since so much of the music of the masters is available on cpdl.org, I rarely purchase sheet music. So, the cost of any music you sing simply depends on what sort of contract you have with your copy machine company and the cost of paper and ink. Same goes with any weekly program you'd want to do. Consult with the parish bookkeeper. He/She will most likely have the per page figures.

Even with a terrible organ, you'll need to maintain it so it doesn't go from being a terrible organ to a non-functional organ (unless, of course, that's what you want to happen :-)). Not knowing exactly what instrument you have or its condition, I would expect you'd need to plan for $500 to $1000 in maintenance for the instrument....others are most welcome to correct me if I'm wrong about that.

I have no idea what a GIA license costs.

If you're bringing in a student, I would pay them minimum wage. If they are a music student, perhaps it could be supplemented with college credit or choral scholar work....such as conducting the choir in your absence or conducting at a rehearsal and on a Sunday that you're their, followed by you evaluating them. There's a lot of ways to pay a student that may be more valuable to them then just cash (although cash is good too...)

Do you foresee any additional musicians that will need to be contracted out (brass or strings or additional singers for Christmas/Easter/Major celebrations)?

Honestly, not counting my own salary, I'm able to run my program for a very, very reasonable cost. It's a complete fallacy that running a quality music program is cost prohibitive. Particularly these days, when so many resources are available online for only the cost of printing them (and then, of course, they can be reused), saying a good music program is just too expensive is a complete cop-out. As long as you have a supportive pastor, a willing congregation, and a music director of reasonable competence, you can have a great program for very little money.

So sorry - let me clarify and thank you so much for your time.
The director (me) does not play - severe tendonitus - , but will manage the parish music program and be giving a series of classes in the evening to the current choir members to help hone their skills and work with them on site singing, ear training, score marking, etc. It's a very diverse parish with a lot of nationalities - so this is designed to help develop average skill levels and bring the communities together to help form relationships between parishioners who are currently not "in harmony."
The parish is in a Major US City -DC - and the pastor has already established a stipend for the organist of $100 per liturgy. (It may have to go up as the current rate ranges to $150.)
Section leaders aren't currently in the plan, but that may change.
I don't know if a license is needed, but I'm assuming there is NO choral library. I'll be moving my own library over - but I'll want to legally use copies if necessary. So, I have to research that.

Weekly programs would be simple, but allow the choir to sing from a wide repertoire.
I'm gathering information because I've been asked to submit a proposal for a job I didn't apply for, but was offered.

It's very tempting because the Pastor is somewhat manic about good music and a proven fundraiser (he built two churches in Portugal - one with the 2nd largest carillon in Europe!) He's also a solid, friendly man with a deep and obvious prayer life. The parish is entrusted to Communion Liberation - and he's a CL priest.

I ran a music program for a historic church in DC some years ago - on a shoestring - and had a lot of success. I'm just trying to get an idea of what other's programs are like and any information on doing a budget....which I don't necessarily enjoy.

Thanks so much for your help.

How's this going, tomboysuze?

At a parish I worked in when I was younger, the budget was $10,000 plus salaries (secretary, staff cantor/handbell director, organist, another organist, and the director). That figure covered purchasing music, recordings, choral subscriptions, hiring instrumentalists, having cantor and choir parties, reprint licenses, snacks for after children's choir, and numerous other expenses).

Seconding what Adam said. Money spent on good dependable section leaders is money well-spent. It has been my experience that the volunteers really appreciate the trained section leaders. I am also a firm believer in choral-scholars, budget permitting.

If you're careful, you can minimise costs by using stuff that it out of copyright or from the various online databases of free music.

Do you mean CC Watershed's Vatican II Hymnal? That contains a solid repertoire of time-tested hymns & is readily available right now!

What is the going rate for a first-rate church custodian these days?