From my understanding,
There are two type of poles.
1) anchored/wall plug to the concrete floor
2) we have to bury it and put cement around the pole.
The measurement of the said area: 8' 5"
Including gate (usual measurement is 3' wide)
So there will be remaining of about 2.25' fence on either side of the gate (8' - 3').
At the edge of the said area are concrete walls.
So, I'm thinking on using the pole and anchored to the wall using L-steel.
For the gate, I have to bury part of the pole and pour cement around it.
Expensive by nearly RM2k. So, thats nearly RM4k in total.
Mind you, previously I quote for the length of 40 feets, and they gave the quotation about RM 4k plus.
Now, I quote for the length of 8 feet, and the price given is nearly the same.
Thats a cut throat.
My budget is within RM2k.

I am not sure how you going to construct the gate or is it ready made. If you have the cutter, welder (maybe no need) , you can diy easily if you the handy type of person, but doing it as nice as contractor will need practice and trial and error. Gate support/pole you need to make sure the depth is good enough to support the structure and movement, that usually need 1.5 - 2ft deep.
They may have charge you by lump sum because of small work. Since cement not going dry the same day, they may have to come two trips.