Mine for me and get paid by hour. I pay good.
The function for payment looks like this:

3600s (1hour) / duration time of your miner (Mininglaser, Stripminer etc) *yield in m\xb3 for that miner * number of that miner module * 80

So for example in a retriever with 2 stripminers it looks like this:

3600 / 180 * 1049m\xb3 * 2 * 80 = 3.356.800,00 ISK per Hour


To book me and my Orca it will cost you 20% of the market value yielded in the op.