2 years for Conventional , 3 years for FHA ( in Florida)
I wonder what area you are in. But here in Tampa Bay area it's pretty common right now especially with low-priced bank owned properties. We get in multiple offers bid almost every time. Of course , it depends what comps are saying. I understand your concern though, some of my buyers used to the fact that they want to negotiate and get it at a lower price, so sometimes it takes for them losing on few deals to understand that's it's normal due to the market condition.