Intermitent starting problem!

[eliwwjd]

Has any body of the members here have reported a faulty start push button?
My situation is intermittent, sometimes it does it, sometimes it doesn't do it.
The problem is that when i hit the push button to start the car, normally car starts fast with no delay problem.
Lately once and then, when i hit the push button to start my car, there is like a 3 to 5 second delay and then it starts cranking to start the car but it takes longer than usual. It wasn't doing this before. The normal behavior has been instant engine start once you hit the start push button.
I took the car to pepboys and they told me that according to their diagnostic equipment battery had to replaced. After this i took it to 2 more places(autozone and another local shop) to have second opinions and to be sure it was battery but on both places they told me battery was good. Mechanic tells me that is not the starter because car is cranking with power on a push of a button the majority of the time, its just a problem that is intermittent. I'm lost here because if its not battery and starter, what the hell is it?
A few days ago a check engine light came on with a P0300 random misfire. Code was cleared but it hasn't showed up on the cluster again. At that moment i had a very empty gas tank and was using another gas, then that day i decided to go back to the previous pump gas brand but still yesterday and today it did it. This is a weird problem and i'm not gonna out and waste money on a battery, coil pack, crank sensor etc. if i don't know for sure what the heck it is. Can somebody share some light here because i'm lost