I'd make a strong run at Amari Cooper.
He's going to be 31 this year. Older, but not ancient.
Just the season before this past one he had arguably the best year of his career with CLE so you don't have to turn back the block too far for a productive season.
No argument that he wasn't good last year. But he spent the first half of the year with a trainwreck CLE team. Tried to do some research and I read a reddit post from 5 months ago while he was still with CLE that 45% of his targets qualified as "off target". No way to vet if that's true, but affirms what I think we all know about his CLE situation. He got traded midyear to BUF where it was a new offense for him, unlike any system and he had a wrist injury a couple of weeks into his tenure.
I'm not saying there aren't red flags or concerns but at this stage of the offseason that's what you get. We currently have zero starting caliber WRs right now unless you're high on Boutte and/or Douglas making leaps this year or think Bourne can turn the clock all the way back to pre injury or have blind faith that Polk/Baker are actually good despite looking awful last year. And even then, hard to think any would be confident that any of them are better than low end starters anyway.
I feel the same way about signing Cam Robinson at LT. Red flags, concerns, all that. These are premium positions, our depth chart is terrible, neither are ancient, neither is that far removed from being solid options, and we have mountains of cap space.