Sadly, i suspect Sunderland would have probably offered him double or treble what we could, and possibly a longer contract. If so, then we can't compete.
Because maybe just maybe the Chelsea lad is better than our lad, and in the event of them needing to play at some point this season, wouldn't it be good to have the best player available on the pitch?
You're making the mistake of thinking (and hoping) like a fan. What is better, a 3 year contract on on £40k a year with promotion bonus/wage increase, or a 3 year contract on £20k a year (with a promotion bonus/wage increase?