is it original battery if the one seller sell is RM30 and actually have same sticker with original one (the one came in box).

and is an old model cellphone has a cheaper price or it's still the same since discontinued model = no longer manufactured?

i couldnt be more agree than this .

is a demand and supply market . if lots people wants , it will be expensive .
example , LG battery is always cheaper than samsung in fact from the source ,

but in certain place like malaysia , LG battery is hard to get , seller tend to sell expensive if they got the source.

u got your point but it doesnt work like tat all the time .
still depends.

you might want to try getting genuine parts from amazon

https://wongmarket.wordpress.com/accesories/