I have already completed How Little We Know in favor of Cachino but never spoken to Mick about their business. I have recieved their secret weapons room from him though. Can I still get the pimp boy?

the Pimp Boy 3 Billion is only available from Mick if you have Wild Wasteland.

nope, with wild wasteland it plays disco music everytime you equip it.

I have it on my toon who has build to destroy and small frame.

anyhow, to get it you have to deal with the Omertas, which is a part of "The house always wins" questline. You have to pass a few speech checks, free a few hokers, pass a few more speech checks, blow some stuff up and do things that i'm not posting here for spoiler reasons.

Edit: YOu have to ask Mick "Hows business" he tells you about the Omerta's not buying from him anymore, tell him "I'll look into it."

Really? The wiki said that WW gives you the item, and without it, you only get caps. :unsure2:

No you can't get it now

http://fallout.wikia.com/wiki/Pimp-Boy_3_Billion

I say hows busines, and ill look into it but i have already put cachino in power and he gives me no speech options. Does this mean its too late for me to get it?

yes