The problem with new computers is that they come with a ton of crap on them. Most new PC users get terrible performance because their pcs are bogged down in bloatware and marketware.
And then, sometimes it all works and sometimes it does not...even when it's new.
Also, they now come with Vista, which is more to learn.
The problem with used computers is that you have to know what you are doing to buy used. You have to test them thoroughly when you get them to see.
My current laptop is a $400 Thinkpad R50 (not typical) that came all set up as new, with built-in wireless, 1 GB mem, 1 year guarantee left on it, etc. etc. I had to return the first one I bought on Ebay (a $500 T40) after thorough testing revealed that the USB ports were truly stuck in 1.1. This indicated a motherboard problem. Also had a sketchy DVD drive. Not obvious stuff. Long story, but the seller was sincere and after 20-30 hours of testing and troubleshooting I was certain it needed to be returned.
So, I saved money, but it cost me a lot of time. Of course, a new pc can have problems too.
My backup is an older Compaq armada (built like a tank) that I got for $250. No battery, no built in wireless, has 2002 level of performance, but plays DVDs and works great!
In sum, computers are a pain in the ass, better consider it a hobby. If you are not up for sorting it out, then hire somebody who does to buy and set up a pc for you to do what you want to It will be worth it. Make sure you have time to sort it out before you leave the country if something is not right.
I did see some fair deals on Newegg on new or refurbished. Checking right now, here's one I could recommend, if you are looking for economy in a new laptop:
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Nothing fancy, but relatively modern and well-built.
Here's a variation on mine:
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No DVD, slow drive and small memory though.
Steve