Yes, it's low. See Table 4 in the Key Household Income Trend report. The average is $7,750 - meaning the figure you entered (i.e. $2,000) is already below average, and the average for the 11th to 20th percentile is $2,480, so $2,000 at the 10.9th percentile level is about right.
If you're interested in comparing personal income of an individual, as opposed to combined household income of several individuals, you can use the other Salary.sg tools - just click on the "Benchmark your annual pay" or "Benchmark your pay by age and gender" links.