I'm sure they charge for that....
It is not out of kindness, the cost is embedded. I have to say - it is very nice to have the piece of mind. There is a rigging technician, install technician, and an applications technician that come on separate days that basically guarantee you are up and running. I called yesterday asking about what seems to be excessive spindle noise and a maintenance tech is here right now looking into it (under warranty). We just learned that a recent design change deleted the soundproofing that was previously on all the spindles. Guessing a bean counter saw the $20 savings and took it at the expense of doubling the sound pressure level. Nuts.
Air is simple, you look at local auctions for a screw or other oilless compressor with low hours, and for a PSA drier for it as well, and then get a reservoir if you do not want to have the screw running all the time. You might find a used unit that is a lot bigger than what you need, but generally those run fine with lower loads.
A good tip is to look for spray shops on auction or closing down, as there they tend to have oilless compressors, or at least the whole regular compressor with the drier and oil separators along the line, plus a decent flow rate as well, just because spray painting a vehicle with dirty or wet air is a very quick way to lose money in rework and fish eyes from moisture and mist. looked at the one next door to me, and that is one nice compressor, plus it is also variable speed for constant pressure, plus it is damn quiet as well.
As you have 3 phase supply ( because you have the NC machine, doubt any are single phase at that size) power is not going to be much of a problem, aside from those weird US specific 3 phase variants because of the split phase supplies common in the USA.
I wish it was that simple.....
A have owned and installed numerous compressed air systems up to 20hp rotaries. I have to balance cost, physical size, reliability, CFM, duty cycle, noise, power requirements, maintenance, and single point of failure considerations. In this case - I only have enough 3ph power to deal with the CNC itself (with some headroom). My primary power is 1ph and using a Phase Perfect digital 3ph converter.
My 20hp Ingersoll Rand screw compressor was VERY expensive in all respects - power and maintenance. It also ran continuously and just loaded and unloaded the pump as needed. I replaced that one with a brand new variable speed Atlas Copco 10hp with an integrated dryer. That one seemed to be pretty awesome and they told me it only generates the air you need, bla, bla, bla.... What they did not tell me is that it has a minimum duty cycle which we did not meet much of the time. 2 years later....the pump seized because there was a whole bunch of water in the oil. Fortunately - that was right after I sold it. Still - the regular service on that one was very pricey.
The smaller 3hp single phase ones are still $4500 just for the compressor - still need a dryer and filters. Blows my weak budget.
Used ones are sketchy in the reliability metric since so few people properly maintain them and they are nearly impossible to inspect beyond the basics. If I have a single compressor - it is a single point of failure that has the potential to shut me down for days.
Piston compressors are very loud and generally put a lot of oil and water in the air. The ones big enough to keep up are bigger than I have space for and sound like a squadron of B17's on a strafing run.
I have an unconventional solution brewing that can meet my strange circumstances of low-budget, noise, available power, size, reliability, CFM, and clean/dry/filtered air. We will know sometime next week.