Microsoft just moved away from old model and launched it's own search engine. They will drop Overture soon. It is in beta now, but expect Microsoft to overcome competitors in a few month/years from now.

RE: PPC - with Google you need to prepare spend $2-3 per click. $300 per day will give you 120-180 visitors. It will be up to you how many you can convert to leads.

This way is "pricy"