One other thing I forgot to mention. There is another option that might not cost as much. You can probably get a motherboard from a site like newegg for around 50 dollars. You would probably need a computer guy to help you pick one out that is compatabile with all your parts and probably install it for you too so that will add some charges. But it might be worth looking into if you want a really cheap fix.
http://www.newegg.com/Product/Produc...25%20-%20%2450
Oh yea, the site is one of the largest sellers of computer parts and from what i remember you don't have to pay any sales tax through them. They are very reputable too and almost all their products have reviews and ratings. I built my whole computer from scractch from parts from their store and it's been running almost a year straight (and I mean ever hour in a 24 hour day for almost every day) with no problems. I think the motherboard I got was about 70ish dollars. If I hadn't planned on wanting it to play videogames and some stuff like that I would have probably gotten a cheaper one.