It is about 185 to 188 SGD. If your medical coverages includes this, you can do it and have them cover.
I have done the swab tests and have gone in to Malaysia to run errands and help my neighbours and friends (turn on power, clear stuff) RGL requires that you do 2 weeks of hotel payment, you cannot stay in your own home during this time under RGL. It helps though that you can actually choose your own hotel for the 2 weeks, so if you block the entire 2 weeks, it won't be very expensive. Plus you can choose it near your home so that you can do errands near it.
I am going in again very shortly. Now doing what i can to help out. Maximise the time when i am back in there to do things. Malaysians in Singapore who go back into Malaysia will have a harder time coming back in unless their company agrees to help them. Malaysians who are in Malaysia and coming out to Singapore under RGL will need to be quarantined in a hotel for 2 weeks when coming back)