Don't Rely on Agents, Become One
DISCLOSURE: I mean no ill will to any of the fabulous Real estate agents (or Realtors) out there. I provide herein only my experience and advice.
I have found that becoming an RE agent is one of the easiest things in America to do as the barriers to entry are tremendously low. Thus, as one might expect, there are a lot of sub-par performers in this field. What's more, the good RE agents are doing big commercial deals, working for home builders, doing million-dollar plus listings, etc. So, if you are a landlord or RE investor looking for properties in the sub-$100k region, it is extremely difficult to find a GOOD agent.
If you have one KEEP THEM, but still consider...
If you are doing more than a few deals a year, why not keep the money in the family. There are fees to become an RE agent. There is a course or two to take, continuing education (relatively minor), state licenses, dues for being a member of the National Assoc. of Realtors (as well as state and local chapters - this allows you to call yourself a Realtor), and their are broker fees. Let me explain that last point.
Broker Fees: Every franchise is different. Every broker runs their business their own way and the fees and way they compensate for deals is all over the place. As a VERY GENERAL rule, plan on $125 a month (includes MLS access) even if you do nothing with the agency that month, these are some sort of 'office fee'. Also, VERY GENERALLY, plan on making about 2% net of contract price for every deal.
I further recommend to not be agent and buyer (though this is permissible if you disclose that you are an agent). For example, my wife and I decided she will be the Realtor and sign as such. I am the buyer (I mostly buy, though in rare situations I am the seller). My wife is more or less a one-client Realtor. She works for family and friends occasionally and is gaining some popularity at our local REI club. She does not seek this work and is comfortable just working for me, as being a Realtor is not her full time job.
Again, I hope I did not offend anyone as it was not my intention to do so.