Depends on Service
Like most people stated here each service is different.
At my part-time job on a third tier service we get one complete uniform each season. Initial hiring you get three complete uniforms which consists of pants/shirt and $75.00 towards belt/boots etc...
At my FT job as a municiple employee I get $600.00 per year for any work related items I need. I buy my tee shirts, boots, belts anything I want and submit the bill to the town; BUT we MUST use all the money by June 30 or we loose the balance.
Initial hiring we got about $1000.