I did a lot of math earlier this year, and you'd be surprised how little most pitchers, other than truly elite starters, matter.
Lopez is likely worth three wins, over the full year, over his replacement. Remember, though, Abel is his replacement, so you can't count those wins twice.
Festa, Banda, and Sands combined just aren't worth much more over a full season than other RP. Their in game samples are tiny and go both positive and negative.