ryhino, I'm going to attempt to answer a few of your questions, hopefully will be of some assistance.
1) For $300, don't expect much, yes you can get online, but don't expect quality video & don't expect to ride it hard.
2) Moving closer to $500 will get you a Lot more, sites such as Newegg has units in that range, possibly one with a 3 year onsite warranty (a business type model).
3) Avoid Acer, everyone whom I knew that had one doesn't anymore. These either broke, or were more trouble than worth. Gateway isn't much better.
4) Specs, for $500, you may get a good i3 or mid range i5 with 4-6GB DDR3 1333-1600MHz RAM.
5) Unless purchasing a refurbished computer, forget Windows 7 in that budget. This OS is in high demand, the same PC with same specs, with Windows 7 will cost $100 more than 8.1.
6) Newegg. OEM's are too pricey. Costco is a possibility. Wait a minute, this is the deal for you if you want Windows 7 under $500 with an i3. It won't last long & it's Pro as well.
7) Only buy refurbished if you can't find what you want.
Windows 7 computers aren't locked down by Secure Boot, nor has as much spyware as Windows 8.1 does.
Some Windows 7 computers, especially Windows 7 Home Premium ones, won't be available after October 31.
If you but a Windows 8 computer, make sure that it ships with 8.1, as Windows 8 will reach end of support as of January 16, 2016, if not upgraded to 8.1. Many customers are having issues with 8.1 upgrades.
Warranty. Get a low cost SquareTrade Warranty for 4 years, it'll be less than what the OEM's charges for 1 extra year & there are promo codes for this. The cool thing about SquareTrade is, if the computer costs too much to repair, they refund the full purchase price of the computer. You're not stuck with an open box or refurb of the same model. You can take that cash to buy new technology with. It's important to get as long of a warranty as possible while new, a 4 year one for the model above, with a 30% discount code, would be around $80-90. This includes a shipping label if needed for you to print when needed.
Recovery Media Creation. It's critical that you create this ASAP after getting it updated, but before uninstalling any junk software. This will consist of 3 to 5 DVD's and possible Recovery Drive also (16GB Flash drive needed). I have both.
And create a Full System Image of your computer when new also, before the install of any extra software, other than MS Office, if needed.
Hope this is of assistance & Happy Shopping.
Edited by cat1092, 10 July 2014 - 11:35 PM.