trade system help!

I did job trade coin reward on my server
but i cant do it good
when i sell goods
Contribution will automatic change everytime
i want edit on it ex:
5 star = xxxxxx Contribution
4 star = xxxxxx Contribution

is there way ?

You will only give the prize when you reach a certain amount of contribution


if you use the community it will be like that, the rest you would have to build a new one to do so by contributing a 3 * 4 * 5 *