Usually if you don't want to wrestle that kid cause it is outside the allowable USA Wrestling Guidelines then they will just offer you your money back and send you on your way.
Cause its their right to combine weight classes. When you get into the upper weights its usually more then twenty pounds.

Then you got to decide...
Pack up drive all the way home or wrestle the bigger kid.
It was alway worse in OK cause the max weight is 285.
We've drove all the way down to Stillwater and have had to give over FIFTY pounds or take back our money and go home.

Always watchout for the childs safety FIRST.
Other then that its all about mat time until we get to Subs so I say go for it and use it as a learning tool.