For the club to keep $500, it must sell much more than $500 so that 30% of that large amount is $500.
Let the large amount of sales be x.
30% of the large amount of sales is $500
30% of x is $500
30% * x = 500
0.3x = 500
x= 500/0.3
x = 1,666.67
Answer: $1,666.67