didn't cross my mind to get a used bike,Try
togoparts.com - Singapore's No.1 Bike Marketplace - Home
for a used one.
Folding bikes, you get what you pay for.
Cheap ones usually don't fold well; poor folding system; cannot push after its folded; hard to change parts; to list a few more common problems.
Even expensive ones, need to check for theses things properly before buying.
Dahon has a cheaper $500+ one, but I'm not interested in foldables, so never try it out.
agree with you, will consider a used Dahon bike within my budget.
thanks for the pointer, it really helps