Statistic sales for prestashop templates?

[MrDavid]

I will start developing new fresh prestashop template... so is good to know how many sales can I expect?

 

If developing new theme tooks 3 months and get just a few sales... then is not worth it at all.

 

Themeforest.net shows on every theme sales numbers.

 

I notice most of the developer here mostly work for local clients and selling here is just a second earning.

 

What is top selling number? Any statistic would be good for starters.