Rockman Battle & Fighters' assessed value

Objectively, how much would Rockman Battle & Fighters' assessed value be, sans instruction manual? It is otherwise complete, with cardboard box, clear cellophane tray, clear protective case, cartridge, even the yellow warning sheet written in Japanese... help me out guys.

seeing as the pocket is now a collecting circus prolly only 15 quid without a manual.

What does a 'collecting circus' mean?

Oh! You’re right! It's like a double negative - both 'collector' and 'circus' mean joke.

Do disregard me; truly - I’m just a fool.