lowry print,signed,the lake,50cm x 38.5cm value please

hi, i have a l s lowry print,signed and framed,it has what i think is called a blind stamp in one corner,its approx size 50 x 38.5 cm ,it is a ltd edition 798/850,it has a certificate of authenticity label stuck on the back and stamped by a fine art auctioneers,its called the lake,i dont have a clue about art and just wondered if anyone could tell me its worth thanks Noreen