The slingbox is a one time cost but we are paying for the cable box rental in our house in FL. So, you would have to figure out if you needed to rent a cable box to be at the slingbox location in order to watch the games. If the games are locally broadcast, then you can just hook up the slingbox to the cable outlet. But that connection can only be controlled by one user, so it is best to put the slingbox in a place where no one uses the cable outlet.
It does have to be hooked up to the internet, so if there is no connection there, you have to buy the device that turns your power outlet into an internet connection. I think it is called a "slinglink" but we found the same thing in a
Best Buy 20 dollars cheaper without the "sling" brand name making it more expensive.
We haven't had any problems with our slingbox. The internet in our FL house can get spotty, which can cause a lost connection, but for the most part we really like it. We have ours hooked up to a DVR so we can watch recorded shows because we are now living in Japan and are 13 hours ahead of east coast time. I'm glad that we have it!