A video capture device that i can plug into my xbox 360 and put video on my computer?

I want a capture device that i can plug into my computer and my xbox 360 to record gameplay. I found the pinnacle for mac but i cant find a cheap one anywhere and one thats not sold out so if someone found one of those that would be great. but if you know a cheap solutiion besides using a dvr because i dont have one then that would be great! thank you.the price limit would probaly be 100&