@WPC2002,
Ur neighbour probably is asking U to share some of the cost; if U don't, he might not do the wall. If he does the wall then it's on his own budget.

U can probably tell him Ur quite alright without the wall or if U do want the wall, or be neighbourly U can always just tell him U don't mind contributing RMX.

How much has he asked for the wall?

@n73me,
TS oredi said the wall is going to be 30" x 4".

@WPC2002,
If U think U can do without the wall and don't want it then tell ur neighbour U don't want to spend the unnecessary $. Tell him ur sorry but RM5k seems to be a bit too much. If U want, U could counter offer another figure and leave it to ur neighbour whether he's going to build the wall or not.

But if U do pay him, he needs to make sure the wall is built

@zyrl,
I don't think it's viable to build 'half' a wall!! Might as well forget about even building it

Plus it'll be such an eyesore on the 'undone' part.