It just depends on how much you like Barkley. If you think he's a #1 overall pick any other year, then don't give up too much to jump up to get Luck (assuming Barkley would be there). I remember earlier this year or late last year, I asked the draft board how likely they thought it'd be for Barkley to leapfrog Luck as the #1 overall prospect, and Slimm (goes without saying, his opinion should count for something around these parts) said he felt it was pretty likely (in so many words). Right now, I think Luck is still the better prospect, but he's had the benefit of working with Harbaugh. I wouldn't be surprised to see Barkley pan out as the better pro QB.
But if you think there's a huge gap between Luck and Barkley, then no price is too high for Luck.
But if you think there's a huge gap between Luck and Barkley, then no price is too high for Luck.