guys i use DBS Altitude and Woman's card to earn my miles so the value of each mile to me is like.. 1 cent-ish? or less? By that definition it seems cheaper now that the miles will cover the taxes? Did i get it wrong?
Can someone kind explain please

I'm very bad with math!
The source of your miles does not influence the value. Suppose you're looking at a 1 way ticket SIN-JFK in J. 3 possible scenarios:
1. Full cash
This will cost you $7,500 in fare + $325 in YQ + $129.30 in taxes
2. Redemption ticketed before 23 Mar
This will cost you 72,250 miles + $325 in YQ + $129.30 in taxes
3. Redemption ticketed after 23 Mar
This will cost you 92,000 miles + $129.30 in taxes
The value of a mile in scenario (2) would be $7,500/72,250 miles = 10.4cpm, because YQ and taxes are paid in both cash or redemption ticket.
The value of a mile in scenario (3) would be ($7,500+$325)/92,000 = 8.5cpm
This is only the absolute value on paper. The perceived value is often way lower, because nobody will pay full cash for a 1 way SIN-JFK in J. Suppose if you were to pay full cash for the same flight, you might want to look at the cheapest fare, which is economy. This will cost you $1,950 in fare + $310.80 in YQ + $129.30 in taxes.
Your perceived value will then be $1,950/72,250 miles = 2.7cpm for scenario (2), and ($1,950 + $310.80) /92,000 miles = 2.5cpm for scenario (3).
The 'real value of a mile' is often somewhere in between, and it varies with route and cabin class. So if someone tells you that a value of a mile can be as much as 10 cents, they're not wrong. If someone else tells you that the value of a mile is only 0.5 cents, they may not be wrong either. The general consensus over the 'reasonable value' of a mile to make a redemption is 2 cents. That is, if you can get at least 2 cents per mile in a redemption, then it's acceptable. If you could only get 1 cent per mile in a redemption, then you're better off paying cash for the ticket.