FW time building is cheaper for that step between private and commercial, so it's cheaper to get your fixed wing certificates first. Then do a commercial RW add-on.
HOWEVER, there is down side. If you want a RW career, all that FW time is mostly useless to you. You'll be a commercial RW pilot with 50 RW hours, and nobody will hire you.
With a commercial FW cert and 250 hours, you can step right in to many entry level jobs such as banner towing, skydiver hauling, etc. And when you hit 500 hours, you probably meet Pt135 VFR minimums and can get into a cargo operation.
What are you going to do with a commercial RW cert and 50 hours? Entry level jobs such as tour flying will cite their marketing programs such as TOPS and say that you need 1000 hours helicopter PIC time. Heck, even the dregs like flying R44s at Myrtle Beach will want 500 hours.
Seasonal cherry drying will get you a few hours. And there are a few other penny-ante jobs for a low time pilot.
And yeah, you can be a CFI. By time you take that 50 to 500, you'll be a very knowledgeable pilot and still have very limited opportunities.
But it's the same as if you went the whole way as a RW only pilot. The only difference is you would only need to go from 250 to 500. And your wallet would be a lot lighter.
So do you want to be flying 135 & working toward a career when you hit 500 hours, or do you want to still be building time to qualify for that entry level tour job over the ditch?