Dude, I just scored the best deal at Best Buy on an HP. It was $1299.99 last week, and the dropped $200 in regular price PLUS it was $300 off! I was completely surprised, but I think today was the last day...
Link to Laptop
If this one is still on sale tomorrow, i would go get it. Otherwise, look for something with similar specs because going too far below this kind of laptop might be tough for even Vista to handle. Look for at LEAST a Intel Centrino or a AMD Turion 64.
Say NO to Intel Celeron and AMD Sempron. They are crap, and will not run Vista very well. Also,
DO NOT dip below 1GB of ram.
Also, at LEAST consider the extended warranty or shop at costco. Laptops are finicky... mind you, i wouldn't spend more than 20% of the laptop price on a laptop. Best Buy's warrantys are way too expensive in my opinion. I used to sell laptops, so I have a little bit of insight to offer.
I hope that helps.