hi guys, thanks for all your reply..
i came back to Sim Lim Square last Sunday to the shop that gave "good" price (IT. Digital - #01-33)
when i asked again the lens price (50mm f1.4) with the same person the price was $490 (it was $340 when the first time i came), and he laughed at me when i said, "you gave me $340 3 days ago and that's the reason i came back here"... i was pissed off and realized that this shop is a "big bull sh**" and the when other shopkeeper came to me and offer me the 50mm f1.4 with mamiya filter for $550, i straightly told him "yeah you can sell to your mother" and i just went out from that "very nonsense store".
went to another shop (India Shop) asking for 100mm f2.8 macro, he gave me $600 and i said, OK i will take one (because the price is good, the general price is about 670).. He let me tried the display lens, it worked good in 40D, check the lens physic, focus and surface it's all good with the international warranty inside it... then he asked me to wait for him to brought me the new lens because the displayed one cant be sold. while i was waiting, he offered me so many other lens and also filters for the lens, but i just said "i only wanted the lens". after waited for 10 minutes, he phoned so many times and then came to me said, the lens is out of stock, then i said "how come? can i have the displayed one", he just told me that he sold it, then i was doing some bullshit test, "how if i buy the display one for $700", he just straightly said to me, OK i will give you for $700.. hahaha (positively bull sh**) but i told him that i only got $600 dollar in my wallet... then i just go out from his shop.
tried Alan Photo, good service but very high price tag..
go to the orient photo and have the general price ($670 exclude GST) and then bought the 100mm f2.8 macro from them since had been frustrated getting so many "bull s***" from the 1st and 2nd stories shops.
NEXT TIME, I'M DONE SHOPPING EVEN ASKING PRICE TO THE "BULL SH**" STORE AT SIM LIM