I already wrote there need to visit their HQ. They dont have HQ in Malaysia.

1  You need to fly or take a train or bus into Singapore.
2. Bring at least SGD10k (to make your journey worth it)
3. Go to marina bay financial center via smrt
4. Go to DBS HQ ask for DBS Vickers account with DBS bank account.
5. You need to open Vickers or else you won't get the bank account at all. It's their requirement. You don't need to fund it or use it.
Take whatever account they give you. Don't bargain.
6. Deposit in the SGD10k.
7. After 6 months and 1 day, open DBS MY account via online.
8.Transfer money into DBS MY account from previous DBS/posb account.
9. Close your current DBS/POSB account online.

You didnt go your homework enough. Come I spoon-feed you
There's only one bank in sg which accept Malaysian without sg address or if you are not working/studying sg.

Cost to maintain account varies from SGD3000-SGD0.00

But you need to be physically there to open account. No online opening account.

That's bank is DBS. But you need to open their DBS Vickers account. After that see what account they opened for you.

If it's a DBS multiplier you need to maintain sgd3k for 6 months.
If it's a DBS My account it cost sgd0.00 to maintain account.

If you get a DBS multiplier account, you can switch to DBS My account after 6 months via online.

Hope that helps.

only require SGD500

nope, as tourist visiting Singapore