There is a great blog from a VC at Redpoint by Tomasz Tunguz. In it he discusses every kind of SaaS business you can think of. He has a great article that analyses pricing over the last six years (read more). The large trend in SaaS is about a 3-4 times multiple of net. Online businesses are typically calculated from their net profit (income minus expenses), so a business that generates $100,000 a year in free cash flow/profit would sell between $300k to $400k.