We see it exactly the opposite and that's okay.  We all know multiple viewpoints work.
In dynasty, I don't want to be streaming FOTM RBs in bye weeks and here and there performances, seeing which ones are Arian Foster and which ones are Andre Williams because the cost is so much greater for a young dynasty RB.
The second that Andre Williams flashed that one big game, his price was 5 times what Charles Clay was, despite him having a couple of good games.  Fast forward a year later and the guy you pay peanuts on is the one worth the price.
RBs come and go in a blink. Just my opinion but when you feel pretty confident you got one, that's the more valuable guy.  Much harder to find and pay for than a TE.  Again, just my opinion and may be unique unto me but has worked in my case.
		
		
	 
I do think that the market tends to undervalue TEs, which means they can often be acquired more cheaply than RBs. But it also means that people underrated just how much of an advantage a good TE really provides. This offseason, I did a big project calculating actual career fantasy value from 1985-2014, and one of the things that I found was, in PPR, a consistently-good TE like Greg Olsen or Alge Crumpler actually provides as much of a career advantage on the scoreboard as an RB the caliber of Rudi Johnson, Willis McGahee, Domanick Williams, or DeMarco Murray. (Obviously with 2015+ still pending for Olsen and Murray.)
According to PFR, Crumpler had five top-12 seasons (8th, 5th, 4th, 4th, and 2nd). Olsen has five and counting (9th, 10th, 6th, 8th, 4th). Tyler Eifert easily has the look of a guy who could match or exceed that. He's young, he's talented, he's productive, he's highly pedigreed, he looks like a star, he's getting fed. Even if he's "just" a consistent TE5 kind of guy, that is still pretty valuable, and also pretty rare.
And there's upside beyond that. If he's more of a Wesley Walls (8th, 6th, 7th, 4th, 2nd, 1st), Ben Coates (3rd, 1st, 1st, 3rd, 2nd, 3rd), or Keith Jackson (1st, 2nd, 2nd, 5th, 2nd, 5th, 4th, 4th) type, he could have value more on par with a Corey Dillon, Eddie George, Ricky Williams, or Frank Gore. And if Eifert winds up being a Jason Witten or Antonio Gates type, (unlikely, but not impossible), he could have career value on par with Tiki Barber, Thurman Thomas, Priest Holmes, or Ricky Watters. There is potentially a *LOT* of value to a guy who performs as a top 3-5 TE for eight years.
Now, this isn't to say that Eifert is that guy. But he's one of very few players in the league with that kind of potential. Gronk is obviously on a completely different level right now, but after him, who? Graham is already 29. Jordan Cameron and Julius Thomas looked like they had a shot, but obviously things look grimmer now. Jordan Reed can't stay healthy. Charles Clay, maybe? In my mind, it's really just Kelce and Eifert who have a shot at being long-term mainstays towards the top of the charts. Those long-term mainstays are rare enough and valuable enough that I'll take some gambles to acquire one.
Obviously I'm a huge Dion Lewis fan, but to me it's a question of whether I think the chances are better that Dion Lewis is the next Domanick Williams or that Tyler Eifert is the next Greg Olsen. And I'd put my money on Eifert. But, like you said, if you miss out on a good tight end, it's perfectly possible to get by with Delanie Walker and Owen Daniels and Gary Barnidge and a steady stream of free options, which you can't really do at running back.