A couple of points/corrections:
First, comparison of recoil of a .50, a Serbu .50 isn't going to come easy. I have not fired a Serbu but have shot a Barrett 99 and 82A1. Neither one felt too much like a shotgun blast to me. I take it that the Serbu is a single shot like the 99. If so, then the recoil, to me, was a good bit more powerful than that of a 12 ga. shotgun, but seemed spread out over more time. In other words, there wasn't the same sort of sharp recoil I get with my 870 and full power loads. Maybe it is the weight of the gun mitigating/dampening some of the recoil such that the recoil actually ends up being spent for a slightly longer period of time. The result being a more powerful push instead of a sharp sensation.
I fully do not understand why folks seem to think that .50 BMGs are more or less fun at given distances. At 200 yards, a lot of rifle calibers are not all that difficult to shoot, be it .223 or .50 BMG. With that said, the .50 BMG doesn't know how far it is being shot, nor does any other caliber. A .50 BMG is plenty fun to shoot a short range. In fact, it feels just like when you shoot it at longer ranges. Why? Because the recoil is the same regardless of distance. If you enjoy shorter range shooting, the .50 will be plenty of fun. Contrary to what I have read and been told, the .50 does not "need to be shot a longer ranges." It doesn't care. If you like what the .50 can do to things a many hundreds of yards, you will be really impressed at what it can do at 200!
With that in mind, there are a lot cheaper rounds to shoot than the .50 BMG that take less of a toll on your body and that work well at 200 yards. Where the .50 shines is by being about to shoot 800+ yards quite well, something most rifle calibers don't do.
What I am saying here is that you should not decide against the .50 BMG just because you are shooting it mostly at 200 yards. You won't be taking full advantage of the gun's capabilities, but then again, most shooters don't take full advantage of their guns' capabilities. For example, I most often shoot my AR at distances of 25-100 yards, urban rifle stereotypical distances, but I can hit targets at 300 and 400, so I am not taking full advantage of the gun's capabilities. That doesn't mean it isn't a blast to shoot at shorter ranges.