It appears from the scant few photos to be an original model 1851 officers belt & plate. I believe I see a bench mark number on the back. See if there is also the same on the keeper. Its hard to give value based on photos but if the leather is in good shape the price is not bad.
Agree with @ucvrelics with one correction - Though these are spiffy-looking plates with the applied German silver (white brass) wreath and all, they're in fact for enlisted men; officer's versions were one-piece and gilded all over. Also, officers' belts teneded to be of sewn rather than riveted construction. This was the most common belt and plate worn by mounted troops (cavalry, artillery) and on a brown buff leather belt was also regulation for infantry NCO's. Your belt looks like a mounted belt and is genuine-of-the-period, remaining regulation until the 1870's.
went baclk to the pawn shop today I offered 175 plus tax and they took it. The numer on the buckle and keeper is 857 and a inspector mark iin the leather is DH. The leather is in pretty good shape From the inspector stamp DH in the leaather is there anyrway to tell the time period it was inspected