Well, that depends if you're gonna use it obviously. It's pretty expensive stuff...Are you going to be editing music and such a lot? Have you tried the free trial? If not, you can download it from Sony's website Here... And Sony's Acid --- page, if it helps at all.
ACID is a very powerful program. I mean if you're really looking for a career in that industry, buy it but get the trial first.
Yea man, you have to know a bit about different sounds, different rates, and ... A lot, I'd try out the trial first before anything, and then go into a program. ~Whit3 Boi