Impossible really to tell...you could use around 400 monkfish maybe less maybe more, depending on your luck, your hp and more undeterminable factors. I'd also like to point out that that's not necessarly true. There are two circumstances where you would not search ONE urn in your 2nd to last room. A) A bad game B) If you're having a mediocre game at 91+ What you should be doing is checking every urn first (or if you prefer, check and urn and search it), then go back and search as many as possible until the time hits halfway, then search the chest and proceed into the final room.