3 y/o AMD. Is it worth the upgrade?

Hey guys and gals. I run a few PCs and I have a desktop that is around 3 years old. On this desktop is a Gigabyte M57SLI-S4 Am2 Nforce 570 mother board. Right now I have a AMD2 dual core 5600+ in it. I've been bumming around on Ebay and I see that AMD2 6000+ and 6300's are available for relatively cheap.

I'm fairly tech saavy, enough to put a PC together and understand more than just the basics, however, I'm not too familiar with bus rates etc. when it comes to overall performance. Would an upgrade to either a 6000 or 6300 processor really be worth $100 or so American dollars for a noticeable performance increase?

I mostly play LotRO and games using the Source engine on this PC. (graphics card is an 8800 gt)

Thank you in advance for your help. :)

id say save up and do the whole faxing (i use faxing instead of a commonly used swear word, fax itself is insult enough) pc gpu, cpu mobo. the 8800gt is on her last legs in terms of gaming preformance if you plan on buying any games from now into next year she needs to go be playing on anything over medium quality. and the cpu isnt that bad but you could use some updating.

if i could seriously recommend an upgrade for you get a nice am2+ phenom x4

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103286&Tpk=am2%20phenom

and then save for a new gpu in say.. end of october beginning of november. then you can get an hd 6770 and rock the block hard for a little while loner.. or a gtx 460

I had a 6000+ Windsor not too long ago and switching to a 955 black was huge and I know bulldozer is going to be a massive upgrade from that but a 5600+ is essenitally a slightly underclocked 6000+ so you could get the same performance with a relatively small overclock which most of those chips can do.