The 215S had a vertical port. This one is horizontal, so it's not a 215S. The 200S cabinet had a horizontal port, but the port ran the full width of the cabinet and had the additional pieces that gave it the "folded horn" configuration. This port does not go full width, and it doesn't seem to have the additional pieces, so I'm sure it's not a 200S. The only other 2x15" configuration I know of (that isn't a variation on one of the above) has dual circular ports, which this one does not. So yeah, I agree with loudthud. It doesn't look like a real Sunn cabinet to me, either. Certainly not one I've ever seen.
As to its value, as always, it's worth what buyer and seller can agree on. My guess is that, in this case, it wouldn't be all that much, as it wouldn't have any collector value. Beyond that, it's a 2x15", which most players these days consider dinosaurs.