I'm not the biggest Mariota fan, but it'd be hard to be upset with that draft. Especially if we don't give up anything to trade up for MM. Dorsett is one of my favorite prospects in the draft, and the 3rd round is so deep with very good RBs this year. My personal favorite is Duke Johnson, but Yelden works too.
No, it's not a great deal. We'd be selling on a great talent for pennies on the dollar because of an injury along with another pick to acquire... a RB that just had a catastrophic knee injury? According to the draft chart (which is outdated, as you see trade downs garnering less value than the chart would suggest unless it's for a QB a la RG3) you're assigning Milliner to have about a late round 3/early round 4 value. That is terrible value, especially compounded by the fact that we'd be taking a RB with a torn ACL in the first round. Why on earth would we sell low?
If Gurley turns out to be the top 10 first round talent he is supposed to be I don't see how we are selling low on Millner.