For sure... that's what's got me leaning towards a gravely. They are cheaper, but there is an awesome dealer near the house.
The lack of service points on a Gravely are why they are cheaper. Those units are designed to be used until broken or worn out, then replace the entire part. There is not much you can "maintain" on them such as greasing and such.
To the OP, as has been mentioned, potentially stick with a standup rider like those made by Wright, or a John Deere QuikTrak if you're mowing hills and such. I like the option of a quick bailout instead of riding it out. With that thought in mind, how many commercial mowers have you REALLY seen with the ROPS in place like it should be AND the operator wearing the seatbelt? Having worked on both, I'd push the Wright over the JD, especially since Wright partnered with JD. How much do you want to pay for yellow vs. green and yellow? Also, having worked on both, be prepared to open your wallet if they need a transmission belt or a clutch. These models SUCK to work on! I'm playing devil's advocate, I know.
For me, overall ease of getting on and off a machine numerous times, low profile, equally distributed weight, cheaper cost, lower center of gravity, and taking up less room on the trailer, I'd choose the Wright or JD model any day over a mid-mount zero turn, regardless of maintenance cost. Since I work for a JD dealer, the popular models are the 648R and 652R. For further capability, you can get those with "Mulch on Demand, or MOD" decks. This utilizes electronically actuated baffles under the deck and discharge chute to go from standard mowing to mulching. Two features, one machine, and no real downtime to install or remove baffles. The only real downfall with these types of machines is the inability to place a large capacity collection system on them. The largest I've seen is roughly four cubic feet that mounts on the discharge side of the deck, versus 8-12 bushel capacity that a mid-mount mower may carry.
With all of that being said, the first and last mower I would ever buy is a Scag Turf Tiger. I appreciate a machine that is designed to be serviced, maintained, overbuilt, and outright performs. Split hydraulics, tapered roller bearing casters, wheel bearings, and spindles, and relief valves on the spindles so you don't blow out the seals from over-greasing. Cooling radiators on both engine and hydro oil. Designed to be maintained! Yes, I mentioned that twice.
Whatever you choose, don't rush into it or be gimmicked by fancy add-ons, overcomplicated designs, or long finance terms. Seriously, JD offers a 72 month option. If you're going to be commercially mowing five days a week, conservatively you'll have roughly 5,000 hours on a unit by the time you reach the amortization of the loan. That's at best two engines ($1500-2400 each), one deck ($700-1900 each), likely the same for hydro motors ($200-400 each side) and pumps ($150-300 per side). These are abused machines subjected to the worst conditions and they will all wear out even if they are maintained properly and timely.
Good luck in your ventures!