Wholesale replacement is sometimes easier than piecemeal replacement of just a few sections. The number of rusted fittings involved can really escalate the labor times.
I've done complete replacements on 4WAL systems which usually involve at least 8 lines. Making new lines with bubble flares in copper/nickel tubing is the only way to go here in the rust belt. That would cover everything from the master cylinder, through the ABS unit, and on to each wheel where hoses connect.
Some shops do this routinely and can be surprisingly economical compared to dealerships and certainly compared to replacement car payments. It may be worth asking around.