Camry :: 2002 - Vibration Feel While Pumping The Brake Pedal

My 2002 camry has a vibration feel while pumping the brake pedal (no other vibration from car). It happens, when you drive slow or fast and stop. Happens when the engine is not even turned on and the brake pedal is just pumped. Its hard to describe the feeling other than zig zaggy on the way down, pulsating, etc. It starts to feel this way on the way down and halfway through the press ends smooth.

I took it to a auto mechanic two days ago and he stated the car had zero brake issues. Rotors and pads are in good condition (sometimes these are the cause for the vibration, but only when driving and stopping), fluid level are good etc. I asked him to test it out and pump it slowly or adruptly, at standstill or while driving, but he still couldn't understand what i was talking about. Researched on the net and found out the likely problem has to do with either Brake booster pump or Master brake cylinder. From a tsb (like a recall note from toyota, see below) , it seemed certain it had to do with the master brake cylinder. I took it to Toyota today and they stated it had to do with the brake booster pump instead , its not worth fixing bc it cost an arm and a leg. Just now i stopped by Active Green + Ross at 110 Gerrard and he stated that its most likely the Master Brake Cylinder, since if you were to pump on the brake while the car was off, turn on the ignition, and if the pedal goes down smoothly , the booster pump should be ok. (it does go down smoothly)
He also stated that for a refurb master cylinder (non toyota) + labour it would come out to 250 bucks. The dealership was going to charge me 1500 for the booster pump and labour. They also advised not to used non toyota parts.

This issue does not hamper safety issues with the car. Its more of an annoyance that i'd like to take care of. I also don't want to pay 1500 for a car with 150k on it.