Mike,
I just went through this with my 15 year old. He sold his mission menace to a family friend and picked up a used Hoyt Alpha. Max 32 with 50-60 lb limbs. He absolutely LOVES it! He has come up with the money difference himself and bought his own arrow rest. I chipped in and bought him a good 5 pin sight. He picked up 20 fps at the same draw weight and he feels like he has grown up with a lot of opportunity to turn in the bolts.
Now, I had shot the same bow in a 70 lb for four years and just sold it a few months ago to upgrade my bow. We had wished I've could find new limbs for it then to give to my son. As it is, we came out money ahead going this route. Either way, I was intimately familiar with the Alpha Max and knew how good of quality it was. Stick with a high quality bow and you may find a deal just right for you too.
Our good friend told him, "you now have a Big Boy bow". He agrees and is so excited about this August. We are going to shoot the Ice Breaker tourney this weekend and we are excited to see how he does. Time to make a sight tape and adjust some pins. He is absolutely money at 20-30 yards.
If you are interested in a new bow, check out the. Hoyt Charger. Heck of a lot of bow for really reasonable coin.
Have fun and congratulations.
Firehawk