#1
I play mostly blues and classic rock and some newer rock as well and i have a pretty low budget but would like to buy some pedals but came across the me-20 that has most of the effects and overdrive that i would buy anyways in single pedals. I was wondering if it is a decent enough pedal.
#2
multi effects dont compare to single effects, i would save up. if your just looking for overdrive definitly get the tubescreamer, its perfect for the music you play.
if you insist on getting multi effects, i'd get the me50 instead of the 20. but you sound like you'd be fine with a tube screamer and a crybaby wah
gear

Fender Standard Tele (with kill-switch)
PRS SE Custom
Fender Hot Rod Deville
Boss DD-3 Delay
Boss GE-7 Eq
Boss DS-1 distortion
Electro-Harmonix Big Muff
Boss CS-3 Compression
Digitech Whammy
Dunlop ZW-45 Zakk Wylde Signature wah