The hard drive: https://www.amazon.de/...00UNA1OBQ/
You could see if you still have a few deposit bottles somewhere in the house or apartment or you can look somewhere where you have not cleaned up.
You can also buy one that you can afford, in the end it makes no difference which manufacturer the HDD is.
That goes well, the extra shipping costs will not be so high.
You still have money left over. Math weakness?
Either you can't do the math or you can't write --- your money is enough.
