I think most of the $7 opening discussion has been centered around opening with Inheritance. Removing 3 junk cards and gaining 3 of a decent $3 or $4 card is probably much better than opening with the other $7s. Obviously dependent on the availability of a good target.
Seeing a Inheritance, Borrow, Baker, Ironmonger board and opening 5/2 is by very rough calculation < 1/1,000,000 odds, but it would certainly be pretty sweet.