...this is a pretty good deal. It's the same lens as we use in class but with an upgraded body for just under $1k. You'd still need to pick up a bag, card(s), extra battery, and any other accessories, but for the price, it's a great starter kit for a serious beginning photographer.
The biggest difference you'll noticed between the 5200 and the 7100 is auto focus performance; the 7100 has a built in auto focus motor, meaning you can use pretty many any Nikon lens and it'll auto focus. You can also do HSS if you're doing flash, so that's a big plus if you know you're going to be sticking with photography. The 5000 series is basically geared towards the "intermediate amateur" cameras, whereas the 7000 line is geared towards the more advanced amateur, and will take you longer to grow out of than the 5000 line.