Seriously, prison sentences for illegally entering the country is grade-A nuts. There's other stuff on there that at least sounds good, but this sounds like "we'll solve a $$ problem with $$$".
By the way, the scheme is already in place. It's part of the limited immigration "reform" that Obama managed to get from the Republicans. There's a minimum guaranteed prison time before deportation.
So the 2-5 years minimum is just bonanza.