It's a 1943 (hence the 43) manufactured K98 rifle, produced by Mauser Obendorf (byf). The three letter code is one of the systems the Nazis used to "obscure" armament production from the Allies - with the intent of making it more difficult to target and bomb factories. I know for bayonets specifically there were three systems used to obscure manufacture, the first was a number code (for example S/172 - for Eikhorn), the second was just using their commercial trademark/name, and the third was letter codes (like fnj - for Alex Coppel). For bayonets at least, it wasn't really all that effective in the sense that everyone knew where the German cutlery industry was located - being that they had been based in the same area for a few hundred years...
Value is subjective, when it comes to sporterized (cut down, or otherwise modified from military spec.) items. Your particular K98 would be a decent candidate to restore/refurbish back to military spec., but it can never really go back to it's original form; and certainly not the original collectors value either. I personally do not know what the value of a sporterized K98 would be, although if it's anything like the value of a Lee-Enfield that's been modified it'll be a fraction of the value of a "proper" example.