Here is an interesting discussion about the need (or lack thereof) for "pro gear" to earn money as a pro.
http://www.fredmiranda.com/forum/topic/1306129
Not sure what purpose posting that here serves.
Pros generally use their gear much harder than amateurs, and replace lenses and bodies on a regular basis as they become obsolescent. It's a cost of doing business. (This is definitely a change from the old days, when Speed Graphics and Leica M3s were used by newspaper photographers for decades, and only a small selection of lenses was needed. My parent's wedding was shot on a Speed Graphic. The photos look great, by the way!)
But the Canon or Nikon "pro" lenses are going to be more reliable and less fragile than Tamron or Sigma lenses, and this is what justifies the prices. Again, pros are not the best photographers or the ones with the best equipment (cardiologists and dentists usually have the best stuff).
But if you make the decision to become a "pro", however foolish that decision may be (yes, you too can be homeless, you too can stand by the side of the road with a sign that reads "Will take photographs for food") don't hinder yourself by using off-brand equipment. He didn't:
http://en.wikipedia.org/wiki/American_Photojournalisthttp://youtu.be/1kqFwVuQ-HgThis is also worth reading:
http://improvephotography.com/1521/20-tips-for-starting-a-portrait-photography-business/and this:
http://www.aphotoeditor.com/2011/05/26/sobering-truths-about-making-a-career-out-of-photography/http://www.smashandpeas.com/10-attributes-professional-photographers-need-to-succeed/Be prepared to make announcements like this (from a photographer I know who lives in my area, a very good one!):
"I regret to inform you that due to financial reasons, we've had to put the studio up for sale.
It's a wonderful space in the xxx area- large and completely remodeled with a connected living area and studio space. Please talk to xxx for more information or if you'd like to get a hold of his realtor."
and this (from same photographer!):
"I've fallen and I can't get up!!!" Okay, it's not that bad but I did fall from a 10ft ladder while working on my new studio and fractured my pelvis in three places"