I'd likely go with the cheaper option. I've yet to try Windows 8, though will do so soon. Honestly, I'm a little confused as to what the actual difference is. I mean, what are the new features, besides the new start menu? Everything else I've seen looks like Windows 7.

My brother is a geek, and has Window 8. So I may be able to help a little.

As far as I know, the only real differences are that Windows 8 is lighter, and therefore runs slightly faster. It has the metro style screens, and it can be on phones, tablets and PCs. He also said that it's very similar to Windows 7.
And if you need more info, I can ask him when he gets home.

I think you may encounter some trouble with drivers, and you'll definitely have a somewhat different learning curve. I personally find the layout out of Windows 8 [Metro] interesting, but I feel that features like 'Charms' and other nit-picks create a counterintuitive and particularly non-functional experience, slowing down and hardening tasks that could previously be done easily (yes there are keyboard shortcuts, so further investigate that, but I'm talking from the perspective of someone using a mouse). Let's just say, I didn't really enjoy it.

This is really subjective, but I feel that while Windows 8 is a step forward in some ways, in many others, it's a large leap backwards. I hate that they basically made an sub-par OS for phones and tablets, bundled it up, and slapped it onto a computer. They haven't thoroughly gone through it and meticulously polished and made sure that everything was up-to-scratch. If you really want to subject yourself to Windows 8, I'd wait a little bit for it to get established. On the other hand, Windows 7 won't be leaving anytime soon, just look at XP.

I have used Windows 8 and its a total bummer!...especially for brickfilming. I prefer Win 7 so much more. First of all the start menu has been dispersed where all the different options that used to be in one place are now scattered across the computer. It's also like a tablet where when you switch between programs, you have to wait for the last program you used to reload/open up again. Not good for brickfilming. It's no longer possible to switch between programs fast because they are not accessible via the taskbar.
   I've also found that it boots up slower than Windows 7. And as far as the best layout for buttons. Windows 7 is SO much easier to use. I do not recommend Windows 8 at all.
   It may be pretty decent for a smartphone or tablet, but on a laptop/desktop its a pain to use.

   

Well, It has a built in camera capture interface that I bumped into when playing around with it at school...
That, combined with the 50% decrease on processor resources could actually make most things more enjoyable.

I personally love the whole thing.

I just heard about the fact that Win 8 has lower RAM/processor usage so that may be a plus for some people, but if I had a Win laptop, I would have plenty of RAM/processing power that it wouldn't matter. I'd rather be able to move quickly and efficiently rather than the system always bugging me.
I think the whole matter has to do with the user's preference and what he likes more.

   

Do you have a source on that? I've seen benchmarks that indicated marginally better performance, but nothing close to a fifty percent improvement- at least not on modern hardware.