Q: took my 2002 suburan to the chevy garage and I told them how I had to put it in park, then neutral ,then back to park to start the

I took my 2002 suburban to a chevy garage because I was having issues with the suburban not starting . I went online and there was another person said he put his suburban in park then tried to start it and wouldn't start then in neutral didn't start then back in park and it started ,so I did that and it started. the next day same thing but then it wouldn't start so I let it set for a couple days then called the chey garage to bring it in. I followed a friend up there while he drove the suburban. Well he put it on the machine and all it said was ABS brake system. then the mechanic said it was starting for him but I told him if it sit over night it would not start so the mechanic let it start over night and the suburban didn't start so he put it on the machine and the machine was suppose to read out bad fuel pump, so I ask how much it was going to cost to fix it and the mechanic said over $ 1100.00 and I told him I would have to save up to have it fix.Can you hit the gas tank and it run

My car has 280000 miles.
My car has an automatic transmission.