1. List their cost; never expect a customer to have to do extra work (like math) to figure out how or what to pay!

2. That's par for the course. Be sure you have enough free sample that a potentially interested customer has a good idea of what they'd get, and prepare to be patient. Building an audience is a slow and rocky road! Also, having a 'trunk' of finished but unsold work can be very valuable down the road, and everything you write will hone your skill, so don't ever consider it a waste to create things.