Take it out on a longer drive. If it starts doing it after a ways, and starts doing it worse the longer you've been driving it, it's the pump.
How do I know? Two trips in a Buick Park Avenue with the pump on its way out. It was fine on short jaunts, but then it would buck just a little on the freeway... Then do it again in a bit, then again, getting progressively worse, and eventually cutting out, forcing you to stop and let the pump cool.
Lastly, about the "fuel pump replacement is a pain because you have to drop the tank" nonsense... I want to know why the heck it's SUCH a chore to drop the tank and swap fuel pumps! It's not THAT BAD. Drain the tank into a gas can, drop it, swap the pump, put it back in, add fuel.
Oh, wait, shops can make people THINK it's a pain, and therefore charge them more! 💡