Turning down a $6M offer for your startup is basically making a $6M bet on yourself... and that's a pretty big bet. Imagine you've spent 5 years building a SaaS company. It's doing $1M a year in profit. Business is growing 20% a year. Then someone offers you $6M to buy the whole thing. You think you can double the business over the next three years and sell it for $12M. Maybe you can. But here's something I'd ask myself. If someone wired you $6M today, would you turn around and spend…