I agree with Stan as it relates to sales and sales feedback. If there are only 80-90 businesses as your local income business base you do need to take the time to go meet with the owners personally and find out what matters to them.
It also sounds like your pricing may be off based on some things you said. It sounds like your pricing is based from the need to make immediate profit rather than further establishing a presence, reputation, credibility and sufficient pay to a salesperson to motivate. I would rewrite the pricing based on focusing on either: a) you selling to eliminate the cost of paying a not motivated salesperson and realizing some profit, or b) you successfully putting one person in the local community to work earning a respectable amount of money. You can hire them as an Independent Contractor.
My speculation, based on some things you said, is that your advertisement options are: a) over priced, and b) you are paying less than 70% of the advertisement payout to your one salesperson as it sounds like you may be focusing on you and not the salesperson’s personal needs. You may also have the wrong person selling for you? Is the salesperson also a friend? Rather than someone who needs to make some money? Rather than someone who needs to build a resume?
I have not seen your sales price options and 70% may be a ‘high payout’ compared to the local newspaper you are competing against, but then again you have a: no real reputation as a company that puts people successfully to work earning a respectable amount of money and you have no real amount of revenue coming into your business to position yourself to compete with needs of those who wish to earn money.