Assuming you have land available that's moderately wooded, what's the ballpark for putting in a good 18 hole course with baskets and tee pads? By good, assume it would be 4 star+ rated on DGCR, ~7000' with the possibility of extending it to 10,000. for pro level play.
Every time someone asks for a ballpark cost, I say "as much as a ballpark".
For T-ball, or MLB?
Thankfully, you have narrowed it down quite a bit. And already have the land.
What's left mostly depends on how much preparation there is for the land and who you get to do it. Figure from $500 to $5,600 per acre, depending on how dense.
There are ways to make it cheaper. For example, let loggers clear cut part of it for pulp. You may break even on those parts. Obviously, you can't use this everywhere.
Sometimes, the accounting practices of the landowner can allow for some of the work to fit under already-budgeted expenses. Like removing invasive species. Or cleaning out dead trees for safety. Or creating "temporary" lanes through the trees to allow access to other construction work. Sometimes, city workers can be diverted from other things without added cash.
On the other hand, a new course may require a new parking lot and driveway, or a restroom building, or fences. Maybe surface water management. Often, erosion control.
No one but the entity doing the actual work can give you a price.
Note that the expense can be spread out over several years. Sometimes that helps with entities that operate under an annual budget. The course will last many years, it doesn't need to be finished in a month.
For the course you describe, figure multiple tees and basket locations and quality signs. Maybe more than 18 holes. Tees can cost $500 to $1,200 to install and signs can be about $100 to $300. Each, not per hole.
Ongoing costs are mowing, forest management, spreading woodchips, replacing baskets (one every few years), adjusting hole locations (maybe one every couple of years, and major re-designs every 10-15 years or so).
The best first step is hire a designer. That's a worthwhile expense to help with the decision of whether to get into the big expenses.