Nah, not necessary. If cheap, sure, go for it. But I am not upset that we didn't pay Jackson. Nor will I be upset if we don't take a RB in the first 2 rounds. Nor will I be if we don't take Bradshaw.
Honestly, the RB position is one of the easiest to fill. As long as you have a group of guys up front that can get the job done, most backs can produce. In the rare instances that you get an Adrian Peterson, the line isn't as important but for 99% of the backs out there, they just need a line in front of them. I would like our guys just fine, if they could stay healthy. And I think behind a line like Denver or San Fran's, they would be putting up good numbers.
Bringing in a RB, with the line we had last year wouldn't do anything... Honestly, a stud offensive lineman would probably do just as much for our running game as a new RB would.
There's a reason that Lacy is prob going to go in the first round, there's a reason he produced like he did. And yes, he is gifted, but that line he was running behind was RIDICULOUS.