Building new PC. AMD Sempron 2500+ What wattage is good for power supply?

[A_DOG73]

I've searched online and found power supplies as low as 22 dollars. Those ones have wattages of 300 - 500. Is that ok or should I think higher? Im building An AMD Sempron 2500+ and will run windows XP with 256 to 512 RAM(trying to figure out the cost) I dont intend to do any major gaming or anything on it. Just for everyday use: Email, surfing, etc. Is 300 - 500 watts enough? Will I run into problems in the future? Any feedback is much appreciated
Thanks

 

[tdeg]

If you aren't going to put a big video card or multiple harddrives in, 300W should be enough.

I wouldn't buy any power supply cheaper than about 50 dollars though (even that is a little low). A cheap power supply doesn't actually put out the wattage they say they do and they can fail and wreck your entire system.

 

[nucleardreams]

Below is a link to AMD's guide for building a PC system. Starting on page 9, it describes how to calculate the system wattage thats right for your components. Theres even a worksheet to help you through your calculations.
Don't forget, alot of USB devices pull power directly from your PC, so you'll have to factor them in as well. :grinthumb
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26003.pdf