Let me guess. You have an oldish bike frame and because retro is in fashion, you think you've stumbled on a sack of gold and registered on here purely to find out how much its worth and make no other contribution to this site.
Dont worry, we see a few of these type of posts per week.
BSO - bike shape object, basically low end stuff.
Saracen were a top uk brand in the nineties then went for the low end market to sell bikes in argos and halfords. Looking at the rear swing arm and shock it appears this frame is from the bso era.
£25-45