Here's an idea I thought up of and wanted to share to you guys.
So level 10 classes is basically an upgrade for the classes you can get once you reach level 10. There could be another room just for level 10 players to purchase a stronger classes, but they will need to purchase the lower class in order to get this upgrade. The level 10 classes will be similar to the normal classes you can get, defender, medic, commando, but with more buffs.
like for example:
Defender class
1 Damage resistance
Speed reduction
to
Juggernaut class
1.5 Damage reduction
Speed reduction
60 Health
and
Medic Class
Can build medic robots
Speed increase
to
Doctor Class
Can build medic robots
Speed increase
have Health pack care package follow if doctor have 100% health
These classes could cost like 500 or 1000 gralats plus the 500 to buy the normal class.