The number 43 was hoped to be retired as it should be, but the number was sold to the new investors that are taking over GEM, and to me is a huge mistake by Nascar to allow this to happen, although Petty's did get a good chunk of change for the sale of the number.
The 43 car will be driven by Casey Kane or Mears....still awaiting sponsorship approvals on both names.

Reed Sorenson well be in the 43 car, with Casey Mears driving the 07 car and Kane staying in the 9 car

I wonder how much the 3 number would be worth to RCR...or anyone looking to buy it ???

I haven't seen of anyone looking to buy it nor have I heard of any recent talk about it. However, I did read on Sporting News that Austin Dillion (Richard Childress' grandson) has used that number all of his career to date, including in the NASCAR Camping World East Series, and there may be a possibility of him driving in the Cup Series, once he gets up to that level. Now some may ask why he was driving the #21 in the Nationwide Series? Well, that was due to the fact that it was a registered Nationwide series number that had owners points to therefore make it easier on the kid.

and of course 21 is a very good #  lol  !! being a huge #3 fan growing up,  i would love to see  the young childress kid in the #3 car,  he is very good so far,  and you know  childress has a very powerful  nationwide program to work him into,  good luck to him.

nascar owns the numbers i believe. rcr only has the right to use it and does not own the number but they do have a trademark on how the number is designed.