Nice idea! I'll be sure to save up some money and buy some pokes off you.
Do you have any set money value's yet? Because although exp is still exp, exp on certain pokes has a higher value than others. For example exp on a shiny map poke has more than a normal map poke. Also legendary exp has a higher value than both. Shiny legendary value has even more. Then event pokes, shiny event pokes, dps and then shiny dps. Other uniques fit between the gap of shiny's and normal's. (dps = donation pokemon)
Different people have different valuations but for me it's: Normal<Metallic<Dark<Mystic<Shadow<Shiny.
Be sure to consider all of these when you finally set prices (if you ever do) and I wish you the very best. The exp game is currently dominated by the botters but I'm sure most people would buy exp off you than botters if given the choice.
I can't believe no-one has posted here yet so I hope you aren't underwhelmed by the current response. I'm sure as you begin to sell and your reputation increases - you'll become a formidable training BEAST!!!
Wish you all the best,