How much do you need to survive in Singapore?

This is just a thought experiment to determine roughly how much is required per month to survive in Singapore for a young working adult with 3 proper meals, shelter over head and basic health insurance. I'm doing this exercise so I can compare my expenditure to this hypothetical example.

I just guesstimate some of the costs below as I think it should be pretty accurate based on my past experiences and I'm too lazy to do research.

1. Meals: 
• Breakfast: Say you buy a jar of jam and loaf of bread which last you for a week ($5 in total). So that's about $0.70 for a breakfast. Let's round it up to $1. With a cup of home-made or hawker coffee, it will be another $1 so total $2. 
• Lunch: Economical rice at a hawker centre ($3).
• Dinner: Again, economical rice or equivalent (for god's sake).. $3. 
• In a month, that's $8 times 30 days = $240 per month (and this is without buying any drinks!)
2. Shelter (or parents' allowance):
• Rent a small room for $500 with utilities and WiFi included (but no air-con). I think it can even be cheaper if you stay in a remote location such as Woodlands or Jurong. 
• -Or- Live with parents either for free or give them some allowance. 
3. Transport:
• $100 for ez-link per month (based on my expenditure before I bought a car).
• No private transport.
4. Healthcare:
• Referring to the premium table here, the Medishield Life premium is only $6 monthly for a young adult in the lower-middle income group. 
• I also assume here you get illnesses and ailments such as headaches, fever,  and cold occasionally, so another $5 per month on average to buy pills (DIY cure). 
• Dental checkup every 6 months: For a typical polyclinic visit, it costs $45 so that's ~$8 per month.
• $10 haircut in one of those express shops every 2 months, so that's $5 per month.
5. Phone plan:
• I will just include this since in this modern age, almost everyone needs a smartphone in a developed country. How can you not own one when the workers and aunties own one each?
• Say $20 for a SIM-only plan with 3 GB data.
6. Gadgets:
• Say you need a laptop and mobile phone and you can only use them for 4 years max. 
• Assume $2000 per 4 years so that's about $42 per month. 
7. Clothes:
• Say you spend $120 a year on clothes on average so that's $10 per month amortised. You'd need at least some decent clothes in this judgmental and superficial world, especially in certain industries. 
8. Entertainment:
• Assume all the entertainment is derived from your mobile phone and laptop.
9. Groceries and necessities:
• Assume $5 per month for shampoo, toothpaste, etc. (amortised)

So in total you'd need $941 per month for a really frugal and financially disciplined lifestyle! Wow! I thought it'd be even lower.

One can probably even reduce this further by cooking meals yourself, DIY haircut, etc.

Mine is 250-300% of this inclusive of owning a car. 

Additional things to sweeten your life that were left out above:

1. Vacations
2. Better entertainment such as movies
3. Occasional splurges on food and transport

How do YOU compare to this?