After reading this thread, we called Canon a few times. Most of them asked me to visit them and would not provide a quotation of the Privillege purchase price of different cameras. One of them even told me that this is conditional, ie must be damaged canon camera to qualify.
I went down today with my old EOS 650 (film camera body) - no question asked, and the lady on Level 4 was super super nice. Very polite and willing to answer all my queries. Now I know We could trade-in any old camera for both still-shot camera (up to EOS 50D but currently out of stock - est leadtime 3 months) and video cams too. I finally went for IXUS100IS - very slim and sexy. Too bad I bought my EOS500D 1 month ago - else could have saved $100.
This is the Privillege Purchase cost gathered from avaliable sources and over the counter :
IXUS100IS - S$373 (MS Colour offer $20 cash & carry), RRP - $469
IXUS95IS - S$317, RRP - $399
IXUS110IS - $436, RRP - $549
EOS500D Body - $950 (bought from MS Colour @ $1070)
All include standard freebies under Canon promotion.