Ask them for a complete breakdown of what they are installing.
This is not enough information and quite vague.

If you look at the line item #8 "1hp - 2hp Air-cond point using 2x2.5 mm PVC cable" this is how the quote should be done so you know what wires are being used. (although 2 wires only? Not 3??)
Similarly, the 63A/4P ELCB should be listed with complete information, and so should the wiring for your water heater.

Look, if I were quoting for a job, I'd gladly list "Water heater point using 3x (L,N,E) 4 mm² MEGA cable with Schneider Vivace 20A dual pole switch (with neon indicator), c/w dedicated Maxguard 20A, 10mA protection RCBO in DB".

You're paying for it.... ask for full information, and in writing. Good luck.

my contractor quoting this pricing for electrical work for my house renovation:
- wiring point: RM75
- power point: RM150
- aircond point (1hp): RM280

assuming it's following ST guidelines, are the prices reasonable?

thanks

Roughly the same price as mine so i guess thats the market price now