I wanted to offer advertising on our site, but only for pre-approved vendors. This will ensure all of the advertising is relevant to the site and that they sell a high quality product. I was wondering the easiest way to do this.

There are multiple payment options like:

1 Month for ----- $14.99 USD
3 Months for ---- $39.99 USD
6 Months for ---- $75.99 USD
1 Year for ------ $129.99 USD

I have the attributes module already.

I was considering offering a coupon to the customer but I am not sure if this will work. Before I put the effort into it, I wanted to see if there are other better options.