but it's good. Ideal would be to have 3/4" copper lines running directly off the main line through the house (which might be 1" or 3/4"), to each plumbing zone (a zone being a kitchen, or a laundry room, or a bathroom).
Off the 3/4" line to each zone, would be a 1/2" line to the fixtures. Again, "ideal" would be no more than 3 fixtures each 1/2" line.
The only thing this "ideal" plumbing structure would accomplish is lessening the chance that when you're in the shower, and someone turns on the washing machine, the water pressure doesn't reduce significantly. Obviously, the 3/4" water line carries more water and can adjust more quickly to a drop in capacity from something being turned on.
Now, if you have a situation where the line coming into the house is 1/2", and then it runs directly to the first fixture, and then runs from there to the next fixture, and so forth and so on, THEN you have an issue. The pressure will never be right for the guy using the appliance at the end of the line, if someone turns on something at the beginning (or more than one something!).
And, you know what, Seema? When I was a first time homebuyer, I tried to cover all the bases, too. And then one rainy morning my husband and I woke up to a basement 2 feet full of water. And as we stood on the basement steps watching our stuff bob around in the flood, we realized that lies had been told. Lawyers were called, realtors were called, words were bandied about, but nothing really ever came of it. "Buyer beware" is generally the expression used most. But in the end, my husband and I funded the price of a small used car for a perimeter drain system around our basement, and everything was fine. We raised our family in that house, and we loved that house, and when we finally sold that house many many many years later, we pointed to the perimeter drain we grudgingly installed years before and got our money out of it at that sale!
Use your own judgement, but know that just like something you'd buy on the clearance table at any department store "as is" will probably need one new button, you can almost bet that you'll end up having to buy all new buttons because you'll never match the ones that exist.
$4,000 in Escrow may seem like a lot of money now, but a plumber is around $65 and hour, plus parts. It won't take him much time to suck that dry. And that's assuming you don't also end up with a clay tile sewer line that's cracked and gets tree roots in it every spring! And in older neighborhoods, that can be a more likely issue.
The payment on the home is the least of it. You can easily spend that amount again on home maintenance every month, especially if you are buying a fixer-upper. Are you and your husband the "handy" types, or are you going to have to call in professionals every time something breaks? That's a question I'd definitely ask myself, because if you have to call someone then you'd better have the income to do that, or you'll be much better off to pay rent on a maintenance-provided dwelling. It's your call.