The Cheapest Singapore hotels are located in Geylang area which just so happens to be the one of the more colorful adult areas of Singapore if you can get past that you will find that the Sing hotels for the size and amenities to be 25% to 40% cheaper for rooms than say Little India or China town and there are allot of them.
Cheap Charlies found this area quite by accident in looking for hotels for ADEX the Asia Dive Expose that rotates between Bangkok and Singapore every year. Once I stayed here I went to Little India and China Town looking for Singapore cheap hotels and for the money didn't even come close. The best you can do is stay at one of the Hostels in Singapore POW Prince of Wales Hostel being the class of the lot with cheap beds in a communal setting of sorts.
To find the Cheaper Singapore Hotels look anywhere between Geylang 10 and 20. You will find lots of cheap food as well being very close to the excellent Singapore train system which will get you to some of Asia cheapest flights from the Singapore airport in around 30 minutes from 5:30 Am till midnight. the train stop you want is Aljuned get off the train walk to the street turn right go to the traffic light then turn left one block and then turn right at the light and keep an eye out for the prices on the hotels that you pass Geylang street 18 near the shell station is where I normally stay for the equivalent of $25 USD a night.
We have found that using the two programs below that we were consistently finding the best deals on discount hotels, the cheapest rooms and budget guesthouses, if there was not a special on the hotels direct site. Hotels Combined search's 30 different hotel booking sites and points out the best rate and Rates to Go offers last minute deals if you are booking at the last minute. Chuck