You may want to try and work out a deal with whomever has the ability to soup it. The deal being that you will hold on to the film until you have x number of rolls for them to process effeciently. Most of the people who do niche processing charge what they charge in part because it is one off and wasteful. If you talk to them you may find that 10 or 20 rolls at one time will allow them to offer a far better price. As it is you will need to spend some money nailing the correct speed and filtration (if needed) prior to burning through 10 or 20 rolls. I have crossprocessed e6 IR and quickly realized that to get a neg that would make me happy was going to take some experimentation and at the cost of false colour IR I decided to pass. It did show promise. I suspect that e4 IR might be equally challenging.