It really depends on 3 things:
1. Do you need help at another position?
2. What is your scoring system?
3. Is there someone who would give you what you needed in return?
1. If yes, then it makes sense to at least consider it. Not sure who your RBs/WRs are, but if you have a glaring hole it never hurts to try and fill it.
2. If it's traditional then passing TDs are 4 pts, while all others are 6. That means if you could land a high-scoring RB/WR plus a solid QB then it might work out for you.
3. I wouldn't accept anything less than a top RB/WR plus a solid QB in a package deal for Brees. For example I wouldn't turn down something like Rivers/Andre Johnson, Rodgers/Megatron, Ryan/ADP, Manning/Gore, etc.
Bottom line: Nobody is untouchable. But you'd better make sure you get enough in return--otherwise you'll be kicking yourself all season long.
Good luck, and please see mine:viewtopic.php?t=449803