I'm not sure where to get wRC+ for minor league splits, but I find this interesting: (numbers from 2010->2013, vs righties / lefties)
2010: .285, .346, .385 / .217, .296, .261
2011: .290, .338, .424 / .266, .346, .351
2012: .299, .349, .412 / .265, .326, .381
2013: .287, .342, .399 / .205, .237, .295
Goins numbers vs righties during the last 4 years are incredibly consistent. Maybe he'll hit lefties well enough, maybe he won't, but his bat would appear to be a legit play vs righties. Maybe you play Izzy vs lefties and end up with an effective platoon at a decent price.