Exactly, to each guy/girl their own, but i like to keep trades real/fair as much as i can. I believe Pouncy plays for the Steelers, and i highly doubt they would trade him for a 33 year old C.
Are you using the EA draft classes or ones from NCAA? With EA's classes you may be able to find a suitable G to convert to a C and develop him over time. However, if you have a C in your sights and want more picks, i always see how far the player is down the list of the top picks and trade down if i can to get more picks.