Taking a listing outside your market area Dallas, Houston, MLS

[Marlon Jimenez]

I just passed my Real Estate Exam and so I am a newbie here. Those of you who are realtors here, if I signed up for NTREIS or HAR, how do you sell between the DFW and the Houston area? Is it necessary to join both HAR and NTREIS? because joining both is about $900+ per year and it not really in my budget right now.  

Does the supra box/key work in both markets? Can I pull comps (CMA) with one MLS system?

My market area will be the DFW area but I have alot of connections in Houston as well.  

thanks