Hi, here are some recommendations from a friend who booked last year. Some of the prices would have changed though.

YMCA(near Orchard Road)
Standard Single S$ 80.00 ++
Standard Twin S$ 90.00 ++
Family (3 Beds) S$ 115.00 ++
Superior Single/Twin S$ 120.00 ++

Chinatown Hotel
Room Type & Rtes
Single Room S$ 98.00
Double Room S$ 108.00
Twin Room S$ 108.00

Please check for additional charges like government tax and breakfast etc.
You can also checkout the chain hotel like

You're not going to get a swish hotel in Singapore for that price, unfortunately. If your expectations aren't too high, Royal Peacock Hotel, YWCA, YMCA and Metropolitan YMCA and are pretty good choices.

If you scour the hotel search pages like , , , , , etc, you might be able to get places like Holiday Inn Atrium which are a class above for under S$150 (that's approx US$100).

If your budget is extremely tight, you can try the Fragrance and Hotel81 chains which normally cater for "quickie" stays where a bed is the main consideration for guests. The seedier ones go for S$60 - S$80 while the better ones in more reputable neighbourhoods are around S$130.

You can check out Emily hotel which is quiet centralised between orchard road and little india.You can actually walk to both destinations easily.