What budget is a must for starting out?

I run a local business and it is service related. Right now I am currently getting new customers from word of mouth and Facebook primarily but I would like to test out google adwords and see if I can get in front of local competition. Is there any minimum budget that you need to spend to see minimal results? I don't mind spending the money to make money but Im curious how much we need to spend right off the bat.

Iv tried Facebook ads but from what iv heard from other local businesses,...

What budget is a must for starting out? WordPress ...