Some of the guys mentioned it, but I'm curious why you need a excavator for a pit that you don't own. If you need a excavator on each end, a truck in the middle, and its just you, I don't see that working. By me the quarries all load you.
If you're borrowing 200k, you better have 100k of your own money/ assets/ equity to operate on. If you don't have that kind of money on your own, you're probably borrowing too much. Yes, you have to spend money to make $, but you have to be realistic also. If you only have 20,000, you don't have any business borrowing that kind of money. Sure, there's all kinds of people that do, but they really shouldn't. They're the ones that when times get tough, end up having to take a bankruptcy and start all over. Not that a bankruptcy is the end of the world either, its just something I'd rather not go through.
You mentioned your "profits" at the end of the year, and how that depends on breakdowns. The equipment is going to breakdown, and when you least want it too. And they can all break down at the same time. Really. The site excavator can launch a rod through the side of the block, and you're going to have to spend 15k, right then, in order to keep working. And it could eat the hydraulic pumps the very next day. The same goes for the dump truck. And it probably won't happen at the end of the year when you have the profits from the year to work with, it could happen on day 2. Have you got 30k to fix it with? Want to go to the banker on day 2 and ask for the money?
They will break when you can least afford to fix them, and /or when you need them the most to finish up a job. Then not only are you not billing money, but you're spending $. That goes back to the having a pretty big nest egg.
Just another what if: You finish your first job, the second job you have all lined up, and now there's permit issues. Every week they tell you: "next monday, we're starting". They may be the big contractor that you really want to get in with and do their work, so you want to be there when they say, but that could go on for a month. Two months. That job may never happen. But even if you only miss the first month, that's a hole you have to climb back out of, and they aren't going to pay you for. I bring this up, because I've had it happen. Multiple times. I even bought a crane for a job that was supposed to be three years ago, and hasn't happened yet, but is "still in the works". That I had a "start date" for. Now I've gone and done a lot of other work with that equipment, but if it was the only job I had lined up, that could get ugly in a hurry.
I don't know how familiar you are with the insurance requirements, or plates, registration, taxes,business permits, etc. But just be aware that it all costs way more than you think it will.
Your dad has 30 years in running his own business, and isn't steering you wrong, listen to him. It doesn't matter a lot that it wasn't in the excavation game, its still a matter of managing expenses and assets and return on investment. Its a lot of $, no matter who you are, to step into another 200k of debt, a lot worse just starting out.
If you want to try it, buy the site excavator, pay to have it hauled, and buy the dirt/gravel, delivered. If it doesn't work out, sell the excavator and go back to work for someone. If you can't afford to buy the first excavator, of the list of equipment you want, you don't have enough $.
As far as the business owning and satisfaction thing. I think if you enjoy working, and what you do (whether that be dirt work, banking, plumbing, or greeting people at walmart) owning a business can be a good thing. If you're unhappy now, working for someone else, I generally think you won't be any happier working for yourself. You'll be just as unhappy, only with a lot more stress and pressures.
Double those pressures if you and your wife are both quitting jobs and doing this "together". If she works now, don't let her quit until a year later, you'll need the income.
If you think owning the business is the way to riches, you're probably doing it for the wrong reasons. I've actually never made as much money working for myself, as I have working for other people. That's the paycheck money, at the end of the year money, not counting what I've put back into the company. But you can't go out and spend money that you've invested in the business, on a trip to hawaii.
I can say that I enjoy what I do, but if I lost it all tomorrow, or sold it all, I would be just as happy to go hop in a seat of a crane for someone else.