I have a that only has one DVI port and I want to set up a dual screen so I can edit pictures and videos easier. My question is, which one should I get? A USB to DVI video display adapter (around 40$) or a self-powered video display adapter (100$+) ? Note: all I'm going to be doing is, web browsing, picture editing and video editing. I'm not going be doing any gaming Please let me know asap, as I'm about to go out in an hour to find a display adapter. Thank you and have a nice day.