peering charges?

to ours" into "we'll be happy to peer with you but be aware that we only send
local routes when we peer at public exchanges, and if you want a full routing
exchange it'll take 6 T3's worth of private peering -- can you afford it?"

This sounds like the right approach, although I'd add some flexibility
that makes everything in between possible. Ie, if you peer at one NAP,
then you get some percentage of the peers routes. If you are at all NAPS, then
you get 100%.