An entry-level Dado blade can run about $100. The $10-12 sawblades can't make finish cuts that are worth a damn, because they chew through the work and tear splinters out rather than making precise nips at the front and back of each grain of the wood. For a saw blade an entry level blade that doesn't do this to your work can run you more like $60.

I know this because I've had to buy a table saw blade to replace a $10-12 one on my wife's table saw that someone threw on there because they were doing framing work.