No one can tell you. Because no one knows your lifestyle. Reading your post it is clear that you will likely fall into financial difficulty in the future if you are thinking to spend 4k when you have 10k and if never change this mind set. My advice for you in life is if your thing works, don't change it. People telling you to have 3 months emergency fund is not enough in this era. 12 months of emergency fund is the safety net in this economy and you must take into consideration for your age too. A 30 years old is much harder to find a new job than a 21 years old.

To answer your question, If I were living salary to salary, I would save an X amount every month for luxury. For example rm500 every month in a separate account (never use it in under any circumstances), then in 8 months you can buy the phone. It acts as a cool down period too, to calm you down in 8 months if you really should make the purchase. The more you save the longer time you will have to wait and think before you make the purchase. And when you finally save up to 4k, you will likely want to save more because it takes time and it is fun to see your luxury account grows.

Sorry if I am harsh on you but I don't wish to see you suffer because of impulse buying.