studio mostly private housing. should be around 2.5-3.5k

with 2.5-3.5k, you have a 2 options.

1. 3 rooms HDB to stay alone.
2. 1 room studio condo with facilities.

You wont get a "real" studio for that price
But there are many renovated houses to resemble small studio apartments

Basically imagine a house made into 8 rooms, each with their own attached bathroom and small "kitchen" corner
Amenities like washing machine may or may not be shared
That's the best you can get if you really need to stay alone for that budget

What he telling u is u can't get any studio apartment in SG with 1.5k sgd. With the current market now no need hope. The people here are rich, 1.5k sgd is peanuts for unit rental.

HDB is gahmen flat a.k.a. low cost housing in Malaysia. 80% of people live in HDB so its ok a.ka.a suck it up if can't afford. But HDB its not your Malaysia version dodgy, dirty, no ppl care cheap flats, some even look like condo style now.

The're no 1 Bedroom HDB for rent to public ( only valid for SG Old ppl and under certain income - such flat are subsidies by Gov )

Your budget 1 - 1.5k - rent master room can d , you want a studio prepare 2 - 3.5k