First of all, I know that obviously yes, a guitar player can play bass. What I want to know is what should I know, as an electric guitar player, if I want to play bass guitar?

Secondly, can you recommend me an absolutely the cheapest way I can start playing bass? The cheapest payable bass guitar and the cheapest bass amp that would sound just good enough not to make my ears bleed.

EDIT: Oh, and for the suggestions, I mostly play Punk Rock.
Last edited by LuchadorMetal at Mar 14, 2016,
Really man just go to pawn shop and get the cheapest peavey bass in good shape and make sure you get it set up well.

then look for a used amp that sounds good.

C'mon man you should know how to do this. The cheapest possible way to do anything is subjective when you qualify it like you did. Just go get some used stuff and try it out for yourself. We cant be your ears.
...it was bright as the sun, but with ten times the heat
Start thinking like a bass player who is a member of the rhythm section (with the drums) and focus on supporting the music, not your need to fill in constant notes. I'm not being nasty here--I went from guitar to bass and that's the hardest thing to wrap your head around. The best advice I ever got was twofold--"less is more" (esp. when you are starting out) and "serve the song, not your ego". Being on pointe with your rhythm is more important than playing the right notes (though note selection is indeed important). But I can guarantee more people will notice a bass player that falls out of the groove than one that plays an occasional "off" note.

Being a bassist is about mindset as much as technique. You are driving the song and defining the chord changes but serving the song is what you are there for.

As to gear there are a lot of fantastic starter basses out there from Squier, Peavey, Ibanez, Cort. look in the stickies above for more advice.

For amplification you need to decide if this is just for practice where 20W will do, or for gigging. For gigging you are going to want 200W or more. Our ears don't hear bass well and bass speakers are less loud so you need more power than a guitar amp. Don't bother with a 50-100W amp as generally they are too big for practice but too small for use with a live band.