[mothered]

me and @mothered concluded that if you are gonna do anything hacking related at all,
a PC for $500 ish will be completely useless.
you will probably want a PC or laptop around the $ 1.000 - 2.000 bracket. the more, the merrier.
RAM should be atleast 16 gig, but thats the minimum, so preferably 32 gig.
you will be amazed by how many tabs you can have and running several pen tests and maybe bruteforce or dictionary attacks etc.
the thing is with graphics card; Nvidia is better. but it doesnt have support for open scource and non proprietary software.
therefore, you wont be doing as much stuff on linux with it; and thats what youre probably gonna want to have.
so whats the alternative? AMD is actually better, for linux.
storage - as much as you want. remember that you'll gonna have to buy a new computer when it runs out. dont format the hard drive, that sucks.
for OS I would simply recommend linux. either with an easy to learn distro, or a hacking distro if you have the courage, and slight bit of patience.
processor - intel core i7.
and also, SSD is much faster. HDD is fucking stoneage man it will slow down your PC and shit.

either that, OR you can buy a cheap Lenovo or Acer aspire laptop. you wont be able to do all the cool pen testing you want, but it will be a good start.
I hope this have helped you. I also just started gettin into pentesting, so Im trying to learn. if youre running linux, I can recommend a pentest tool called leviathan.

peace.

Well said.

I'd just like to add that you need to allow for expansion with your future computing needs. For Instance, 16 GB of Ram may serve you well now, but not enough If you plan to perform demanding tasks In a couple of years or so.

yeah, also a good point, atleast if its a stationary.

My post Is based on personal experience of upgrading my systems every so often.

I always allow enough resources for future computing needs.