Try Racket World in Pertama. Thats where I got my Aermet 5300. Most likely you wont find any of the newer models, most of the shops seem only to have GraPower series and Roots 2000. I was lucky because I specifically asked the shop owner if they had the Aermet model and luckily they had 1 in the back
RM300, which is the "real price" since they list the prices higher than they actually are. Im not sure if they would have another 5300 but there was a 3400 which they had as well for RM250. Personally while the racket has awesome feel, it seems like it takes some time to get adjusted to, so depending on what other rackets you use, it may not be a good choice (unless you are willing to make it your main racket and therefore adapt to it)