In short, this field is a massive ripoff. They charge $160 for a case of ordinary Draxxus, and don't offer HPA fills, so you can only play with CO2. Another example of their ridiculous prices is the Angel they are trying to sell. It's an old, used Angel worth $300 at most. They have been trying to sell it for $1500 since they opened.
Overall, you are far better off to buy some paint downtown and go play in the woods.