Newbie Question about Upgrading OS

Hi I am a poor student so I am currently using 10.2.8 on my computer. It is now so old that I can't download new versions of web browsers etc. so I know that I NEED to upgrade. I have a fairly old 1GHz Powerbook G4 with 512 MB of Memory. I have heard that the latest OS 10.5 significantly slows down the older computers and was trying to figure out if I should purchase an older operating system such as 10.4 or if I should get 10.5. Also I was looking into buying 10.4 and the person selling said I would also need to buy 10.3 because I can't upgrade directly from 10.2.8 is that true? I looked on the mac site and it didn't say anything about that, just that I needed a G3, G4, or G5 and that I needed 256MB of Memory and 3GB free space on the Hard drive. I am sorry if these are dumb questions, I don't really know much about computers, so thanks for your time. If any of you can help me I would really appreciate it!

I'm pretty sure that the guys wrong, but I might be wrong, anyway i suggest 10.4 leopard would definetaly bog you down.

I would suggest a clean install of which ever version of OS X you get. I would go with Tiger in your situation. Why? You mentioned you're poor so Tiger will be cheaper, 512MB RAM is pretty small (it meets only the min amount of RAM for Leopard), and you're barely over the min processor speed too.

I have the same PB with the same specs, and Tiger runs nicely. You could purchase Tiger and install it on your PB, there is no upgrade path.