One last thing I'll say is that players like Charles and Peterson tend to appeal to a certain type of owner, but they don't necessarily have great trade value to every owner (because the age will scare away a lot of people). So even though they might go at X spot in drafts, that doesn't mean they'll trade as well as the other players in that range. In the case of Charles, I think you'd find that he's harder to trade than Julio, Graham, or Demaryius. In the league where I passed on Charles for 1.03 and 1.10, I offered 1.02 AND 1.03 for Julio or Demaryius (to two different owners) and was rejected without much interest.
This is a good point. But I don't think it's just his position. It's true that a lot of owners have figured out that overpaying for veteran RBs is a mistake, but that doesn't mean there isn't a market. You just might have to offer a selling price to make the move.One of the things I've learned in trading is that there's a selling price and a buying price. If the Charles owner wants to move him, you'll get a better price than if you inquire about Charles from someone who doesn't want to trade him but will listen to offers. So in your case, he came to you with a pretty cheap offer - 1.3 and 1.10 seems way low - but you weren't interested because you weren't selling your picks. I'm sure you'd listen to an offer for 1.3, but you'd want more for it than most owners. On the other hand, if I had 1.3, I'd be looking for opportunities to get value for it. I wouldn't hate making the pick, but I'd rather trade it for a known commodity and let someone else chase the shiny new penny. So even though I think Charles is a sell high, I would still make that trade, because I'm offering a selling price for my picks, and I'm getting a selling price for Charles.
You can add a lot of value to your team through trades by always getting a selling price for whoever you acquire. Just keep trading and trading and always get the better end of the trade. You'll end up with a lot of good stuff, but it won't be the guys you specifically like. I don't really like players. I like bargains. I've only traded up once to get a player I liked in the draft - and that was a guy who had slid beyond where he was supposed to (Montee Ball at 1.10 last year, after Franklin, Michael and Lattimore, among others). So while I paid the full buying price for 1.10, I still paid less for him than I believed he was worth.
You should only pay the buying price for guys you believe are underrated. Julio and Demaryius Thomas aren't underrated. The picks you have aren't overrated. So in my mind, you were offering close to the maximum price for them. It's not a bad trade, but it's not a trade you needed to make, either. Fortunately for you, they were asking for the maximum buying price, because they didn't want to sell. And I don't blame them for that, either. Like the Charles owner, they've probably built their teams around the idea that they'd have an elite WR now and for years to come. Starting fresh probably doesn't fit their team.
Which is why, if you're ambivalent to which WR you get in a tier (maybe Julio, DT, Green, etc.) then your first offer should be to the guy whose receiver is the worst fit for his team. A rebuilding guy obviously could take the draft picks. But a veteran team in win now mode might not want to start over at WR. The thing is, he might be willing to take a veteran WR and 1.2 for Green, while the Julio owner might be building around him as a cornerstone of his team and just bought a Julio Jones jersey. So before I offered 1.2 and 1.3 for Julio, I might look at the Green owner and say hey what would you think about 1.2 and Andre Johnson? Meanwhile I'm floating an offer of 1.10 for Andre and a second, and haggling with that owner in case the Julio owner says yes. Now instead of offering 1.2 and 1.3 for Julio and getting turned down, I'm paying 1.2 and 1.10 for Green and a second. And who knows, you might be able to offer Green for Julio straight up if that's what you really want.
Which is why I think it's a mistake to pay the buying price for anyone that you don't think is significantly undervalued. Add the talent first, as cheaply as possible, then move it around to assemble the team you really like.