If you're not happy with the price, terms, or having non-exclusive rights, walk away. I'm sure you could find an artist to do something with exclusive rights for cheaper.
The "significantly higher" price will be based on how much he thinks he can milk your prospective commercial company for, plus headroom for negotiation.
The "significantly higher" price will be based on how much he thinks he can milk your prospective commercial company for, plus headroom for negotiation.