Is there a small version of land development, or is $2M the entry ticket?

The two lot split is real and it happens constantly, it just isn't the same business as the 60 lot one. It's closer to a paperwork project with a survey attached. Where it goes wrong is access and utilities. If the back half has no frontage on a public street, or the sewer main is 300 feet away and the tap requires cutting the road, your $8k paperwork project turns into a $60k one. Ask the city two questions before anything else, does each proposed lot meet minimum width and area, and where's the nearest sewer and water main.

$50k with not much money leaves out that you have to own the lot first, and a lot big enough to split in a neighborhood where the halves are each worth something isn't cheap. That's your capital, right there. Also budget for a survey in the low thousands, the plat application fee, and a title update. On the small version people forget the title work and then find an old utility easement running straight through the new buildable area.

Taking your terms one at a time, because they get used loosely and it causes real confusion.

Entitlement is the whole set of government approvals that make a specific use legal on a specific piece of land. Rezoning is one possible piece of it. If your land already carries the right zoning, you might need only a subdivision approval and a site plan, and people still call that entitlement work. So rezoning is a subset, and hearing the two words used interchangeably is the loose usage.

A plat is the recorded map that legally creates the new lot lines, with dimensions, easements, and any dedicated street. A licensed land surveyor prepares and seals it, and for anything with new infrastructure a civil engineer prepares the construction plans that go alongside it. The city reviews, approves, and then the plat gets recorded at the county, and recording practice differs by state.

For a straightforward two lot split with existing street frontage and utilities in front, you're typically paying for a boundary and topographic survey, the plat drafting, an application fee, a title update, and a few hours of an attorney's time. In many markets that's a few thousand to the low tens of thousands. Add a sewer extension or a shared driveway easement and it climbs quickly.

You generally don't need a real estate license to develop and sell your own land, though licensing triggers vary by state and are worth confirming with a local attorney. What you will need is liability coverage once anyone does physical work on the site, and your contractor's insurance certificate names you.

Start by reading your city's subdivision ordinance. It's free, and it answers most of this.