Hello AM Hanson!
What gaming console did you want to record? Because this could change which capture card is the best one for you.
There are many capture cards out there now days that you can capture gameplay and record commentary at the same time using the software that comes with the capture card.
I have a capture card myself and use it to do the same thing.
I made a few articles that would help you with this subject:
6 Cheap Capture Cards
Best Capture Cards with HDMI
The video quality you want to record, will be a major factor that will make the price vary.
Let me know on Hubpages or my website if you have any questions!