@ taeception - before any suggestions can be given, you'll need to help refine the query.
- fixed blade or folder?
- what purpose? (this may affect fixed blade or folder)
- carbon or stainless steel? are you good at maintaining your blades? or do you prefer something that you only need to sharpen once in a blue moon since it will not be used?
- if folder, do you prefer a certain type of lock - lock-backs? liner locks? framelocks? slipjoints? doesn't matter?
- is there a particular look or style you like?
For about USD100 (SGD130 approx), you can get a wide variety of both folders or fixed blades (some customs even) that are value for money. For folders, think Spyderco, Benchmade (there's a store at Beach Rd run by Tay of Hornest), Kershaw and many many more plus of course the whole gamut of Chinese copies (which are good just that they infringe the IPR of many companies).
Cold Steel American lawman with a 3" blade is not a bad knife, the tri-ad lock is very highly rated, the AUS8A steel is very easy to sharpen, but it doesn't hold an edge very long, so if you're using it the whole day, you may have to touch up every once in awhile.
There's also buying used knives in the aftermarket, that may bring some more reduction in prices, but you may need to know how to clean it and sharpen it up.
My default if you do not know what you want is to suggest the following:
- Spyderco Delica (if you want to keep at 3")
- Spyderco Endura (if you want more length as it has a 4" blade)
- Spyderco Dragonfly, Persistence, Tenacious
- Benchmade Griptillian
If you stick to 440C, N680/N690, 154CM, ATS34, CPM154V, VG10 for the stainless, you'd be good to go - all of them will deliver better performance than AUS8A with decent corrosion resistance for Singapore's climate.
For carbon steel, they are much easier to sharpen and tougher (if heat treated properly) and simple steels are great for field work, for eg. 10XX series, O1. They'll rust so you'll need to either use them often or patina them from day one (mustard or acid) or oil them.
Refine your parameters, I think you'll see many suggestions coming.