I'm hoping that you could forward me to the right shop to get a cheap bike + indoor trainer for indoor cardio. I will rarely take the bike out for a leisure stroll around the parks. What's your top choices? Please do include the pricing. When I say cheap, I mean I don't care much about its features other than it fits me properly and is comfy to exercise for 1-2 hours.
I did something similar to you - borrowed an old unused bike and bought a (somewhat cheap) trainer from crc.com + a mobile phone holder from Qoo10 and now I've got a nifty personal cycling machine that I could pedal and watch my favorite shows instead of sitting in front of the tv with a beer in hand.
So buy second hand, since you clearly want the most value option available. Get a rusty throwaway Aloeca and trawl togoparts.com, gumtree.com.sg and ebay.com.sg for used trainers.