JobRoller already has functionality built into the theme to allow to to charge employers to list jobs, so if you're referring to also adding items to purchase within JobRoller, then that would require customization. Please feel free to clarify if that is what you mean and we can confirm.
In terms of modifications though, AppThemes does not offer customization services, however we do have a
certified partners page where you can find developers for hire. If you make contact directly with an outline of your requirements, they will be able to provide a quote for the work. Thanks.
