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...and a good size drive as possible and you will be happy with it for a long time.

If I already have a desktop computer with 250 GB remaining in HD space, is it really critically important that I pay for more than the 80 GB drive that comes standard? Especially in light of the relative prices of upgrading the internal drive and buying a portable drive? It appears to cost $120 to upgrade from the 80 GB drive to the 120 GB drive, whereas apparently decent 120 GB externals can be had for about $70 more (certainly less if you shop around.) Admittedly, I've never owned a laptop before but buying the external seemed like the most economical choice. Anybody who wants to correct me is free to do so though.
 
If I already have a desktop computer with 250 GB remaining in HD space, is it really critically important that I pay for more than the 80 GB drive that comes standard? Especially in light of the relative prices of upgrading the internal drive and buying a portable drive? It appears to cost $120 to upgrade from the 80 GB drive to the 120 GB drive, whereas apparently decent 120 GB externals can be had for about $70 more (certainly less if you shop around.) Admittedly, I've never owned a laptop before but buying the external seemed like the most economical choice. Anybody who wants to correct me is free to do so though.

You're correct. You won't fill up an 80gb hard drive unless you're ripping movies or have a big music collection. Or if you're a professional artist or music engineer, in which case you wouldn't be looking at this laptop anyway. My Thinkpad has a 40gb drive. It took me 3 years to fill it up, that's with music and some movies for the airplane on it. I bought a 250gb external drive for $99 a while back... sweet deal.

By the time you do fill up 80gb an external Terabyte drive will be affordable. At my pace anyway. It's not worth it to buy their RAM either, you can buy it online and install it yourself in ten minutes for 1/2 the price.

The general rule of thumb is to wait as long as possible to buy something. Prices never go up, they stay the same - only the speed & size increase.
 
The Western Digital MyBook Pro externals seem to be pretty good for the money.
You can easily pick one of them up at NewEgg.

The only time I recommend a larger internal hard drive in a MacBook is when you plan to run OSX and Windows via Boot Camp on a fairly regular basis.

The problem is that the default install of OSX takes up quite a bit of your free space and then the Windows partition on top of that doesn't leave you much free HD space to work with.

Fortunately you can custom lean install OSX and free up quite a few Gigs
of space.
 
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