Not helo, but I know a thing or two about the aviating bidness. Seen the bad side, good side, bad side again, then the good side again.
Two of my best friends were high time, very experienced Army pilots. They now fly fixed wing jet aircraft and and they had to bust their ass to get there.
For any good helo job, you need a couple hundred hours PIC in complex, turbine type equipment.
For that, you pretty much have to be military trained or very rich or well connected. Your competition will be those guys currently flying the Blackhawks, Chinooks, Cobras, Apache and Sea kings, in all weather, and under fire.
One alternative would be to get your fixed wing tickets, then get hired somewhere which will pay to get you dual rated. Border patrol, State police etc. Just read the part where you are a full time LEO. Does your unit have an Aviation Dept? Those are the guys you need to talk to. Talk to every LE aviation dept that you can, and find one you can transfer into. Be prepared to relocate.
As far as costs, the flightschool can tell you, but be advised that nobody gets rated in the minimum hours. Figure on twice the minimum hours if you are training part time.
If you have a ton of money to spend, and don't need to make a living at it, you could probably get a job as a flight instructor.
Best thing you can do is go to every local helo operator you can find (not the flightschool) and talk to the pilots about their backrounds, income, lifestyle, and career expectations.
Rotory or fixed wing, all Pilots love to talk about their aircraft and themselves.