Depends on what material you use to pave it, and obviously the land itself, aswell as hiring a construction team to do it, and rent of construction vehicles, fuel pumps which will be expensive, including suppliers, you would probably also need fencing and security, and the basic materials for a basic hanger.
If you really wanted to work out how much it would cost, you could look up the price of a square foot of the material you want to use for the taxiways and runways, then you do the basic calculations and you add the other stuff, but it depends, if you want the airport for private use, it would be a hell of a lot cheaper then for public use. But overall, it’s going to be expensive, extremely expensive.
Depending on how private you want it to be, you could earn money from it.
If you had a couple of hangars, you could rent out hangar space and outside parking to raise some money.
If you had fuel there, you could sell it for a few cents profit per litre.
Also see if there are any gliding clubs nearby. If you are near any hills, you could let gliders operate there, which could raise some cash.
Not huge amounts, but every little helps to keep it cheap to run and sustainable would be a bonus!
Owning a private airstrip is a business and not just a hobby (unless you have millions of dollars lying around). It’s very hard to estimate how much building an airstrip will be; mainly because there are tooooo many variable costs, such as where you live and how much renting the land will cost.
I don’t think you’ll get much from the forum as none of us (as I’m aware) owns a private airfield. I’d say Google is your best bet when finding answers to such questions.
Good luck on your idea anyway! (Maybe pitch it on Shark Tank one day (; )
Personally if I was going to do something like this, I’d start off with just a mowed grass airstrip, and a small parking pad. and then as I save up money, I’d make it more nicer (asphalt, etc.).
Honestly, if you want it exactly the way you’re saying, I’m pretty sure it won’t come easy. And considering you’re only 19 years old, you’re going to need a lot of money to do what you say you want to do.
But I’m not stopping you, if you can find the funds, by all means do it!