MacBook Aluminium 5,1 from MacBook 2,1

Hey guys, I'm back....
Well I haven't been updated with the mac scene but i'm sure nothing big has happened.

Okay so here's the deal.
I'm selling my laptop for a very fair price.
I have a mint condition well cared White MacBook M-2007

2.16GHz C2D
2GB of Ram
120GB HDD
and Superdrive
I'm selling it for about $699
Because it looks really great, clean.

I'm going to buy my Producer's MacBook Aluminium which looks amazing.
I've tested it out everything. every weekend i'm at his studio.

So his specs are
2.0GHz C2D
4GB of Ram
250GB HDD
SuperDrive
and Nvidia9400M

Well... I was just wondering is the MacBook aluminium worth it for
$750
He's giving me everything with the box. and an extra charger.

Thanks Everyone!

Okay, Well i'm actually just going to need a faster computer.
I'll probably get the new version by summer, I don't have a job yet.
I'm a full time student so.

But thanks though

So how do i know if it's the Old screen or not?
Thanks
I would like to know the difference between the 'new' and 'old' screen for the aluminium macbook

Thanks

Sorry to dobule post
But I just got the MacBook Aluminium
Everything works
but the mic seems to not be picking up noise...
What should I do?

I talked to him, he said He'll give me full refund.
and take it to the apple store.
What do you think is wrong?
and also is there any way i can fix this?