If you have the depth at RB, I'd trade him for Megatron in a heartbeat! Hell, I'd make that trade even if I didn't have the depth. I'm not sold on TB and Martin and Lynch looks like he could be riding back spasms for the season but should still put up big numbers.
12 team auction (100$) Keepers (73$): Wilson 3$, Foster $30, Charles $16, Tate 2$, Hillman 2$ Boldin 3$, Britt 5$ (drop), Gronk 9$ Tucker, K 1$,Tynes, K 1$ Jets D, 1$
Rights : Newton Dwyer, D. Thomas J. Nelson, Garcon, G. Tate Giants D
Not straight up i would want a package of a rb with a wr/te. I like spillers upside, although his value is hard to gauge depending on how Fjackson comes back, but I think lynch is the safest of the bunch. Last year analysts said to keep CJ2K and wait for him to break out and that didn't happen. Look for a package and i rate them as Lynch>Martin>Spiller but i think spiller has the most upside if Fjackson doesn't come back
I would say hold on the CJ for another week or two. Right now you would be selling him way too low. I would wait until he has at least a better game, if not a good-great game against a poor run d or something, then try to sell him off high as an elite back.
To answer the question I also rank them Lynch>Martin>Spiller currently but I think Martin and Spiller both have about equal amounts of upside. I mean we haven't seen enough Martin to really gauge him.
I think all of those backs are in the same tier, low end #1 rb's. Too me the most consistent will be Lynch. Martin is the rookie so he will struggle at times. Spiller I'm not sure you can count on every week and too me he is better in a ppr. CJ should rebound this week and play more consistently, but I don't think he'll get back to his CJ2k form. I'd take Lynch. Good luck.
I've been offered to trade away CJ0K as well. I'm being offered Jimmy Graham and Antonio Brown and I'm about 75% a go on this trade. Just worrying that CJ will turn it around and make me sorry...
As for your trade, I probably wouldn't give him up for any of those RBs. With CJ's potential being higher than any of the three being offered, there needs to be further compensation, as others have stated... a mid-tier WR or QB if you need a good backup.