went to see a lot of games in Argentina earlier this year. Didn't get to see BJ in the Bombanera as no games when I was in Bs As but I did visit the stadium. It's very easy to get to the stadium and the area around the stadium is safe so long as you take reasonable precautions like not flashing expensive camera's etc etc.
Did the stadium tour which was cracking. You can buy tickets pretty cheap for the games depending on where you are prepared to sit. On your first game I suggest going with a group from a hostel although even then it can be a bit ropey sometimes. My first game was at the Maracana in Rio with a hostel group and it was awesome. The rest rest I did with friends.
BJ vs RP tickets don't have to be madly priced. We got some for 80 peso's for the game in Mendoza. It was a pre season match kind of like the Community Shield. My bus was late and I missed the game. Wasn't that bothered as it was only 3-2 with 4 sendings off and 2 penalties. Honestly, not bothered. 

If memory serves me correct the game was the first w/e in February so it might be worth checking out if that game is on again. The stadium there was a 40k capacity in a bowl which was awesome. Got there late and hung around ground for a bit.
Worth going to see teams like Tigre just outside Bs As. If up north then and San Juan you can see San Martin or in Juay Juay (I can't recall spelling sorry). Maybe in Rosario you could see some good football too as they have a few teams.
Anyway, whatever you do, do not miss a football match. Even the 3rd and 4th division games are good for atmosphere if local rivalries.