his cost is something high so...
what do you think guys? i should buy it?

There is a very simple way to determine if you should buy it.
Step 1: look at bank account.
Step 2: look at price.
Step 3: subtract price from bank account.
Step 4: is the result good enough to survive two more months without any additional money?
IF yes: buy.
IF no: don't buy.

Well if you want a proper answer, it would be better to give the specs of the laptop.
I was on the Alienware website, and there are a lot of variants of this particular laptop. Which one do you want ?

Personally, I would not go for an Alienware. Their laptops are heavy and super expensive.

If you absolutely want a laptop, better look at what Asus does (being the ROGs or even regular ones). And if you plan to transport it regularly, stick to 15" maximum. Over that limit, they become quite heavy, I speak from experience
The best option would be to build (or ask someone to build) a desktop computer. They are cheaper in comparison to a laptop with the same performance.

For now I have a laptop, gonna change for a desktop in a few days. Here are my current specs (the laptop is 5 years old), it cost me 1000 euros back then
Asus N550JK
Intel Core i7-4710HQ (2,5 GHz)
1 TO HDD@7200 rpm
GPU: Nvidia GTX 850 M
RAM: 8GB DDR3
FULL HD 15.6" screen
Blu-ray reader
Backlit keyboard
Full USB 3
(yeah it might sound lame now, but back then it was an excellent computer, relatively cheap considering the quality. It still runs well)

If u really need then just fulfill your need,