oh yes ive learnt that trick, haha. and thats good advice too, for anyone moving to the philippines.
I am learning bisaya, but its silly to walk in somewhere and start with Bisaya, as they then start talking in bisaya and I can only understand so much.

ANd Yep, i used tht trick to get the headgasket and rings, i have a piece of paper, and i scribble down the storename and prices in front of them, and then move on too the next store, it gets cheaper and cheaper the more text they see written down on the page.
First shop wanted about 1250 for a headgasket and 900 for rings
Second wants 1450 for gasket and 800 for rings (allbeit a better quality gasket)
Third shop, I put the paper down in front of them and didnt let the see the prices in any detail, they spent some time walking around obviously asking each other if they should charge me stupid silly foreigner prices. The price ended up coming down to a total of 1200 for both parts.

Cant seem to have such luck with prices on a radiator though.