Actually according to my understanding on network architecture might not be quite true. The frequency of the LTE can be customized based on a range of release, such as from 1800 -3000mhz to listen from the network.

I know it is a bit technical but Telco won't be fixed to only one frequency, so Samsung reason of not to released LTE which might not because of infrastructure but also global stock on the spare parts are not enough to supply, that is why MY only have 3G version instead of LTE.

LTE will take a few years to deploy whole country probably, but the cost would not be too high as in other region, the LTE charges is same as HSPDA charges, which is just a data plan to them. Of cz not all the countries but mostly practice that.

I also interested but I dunno how to apply, I will pay a little bit more to the shop who can help me to apply it

If he will

Not possible for new phone lo, but wait for a while probably yes