IF you go before the court over it. You CAN always agree to a lower amount if necessary. CS is one of those things that is NOT set in stone and can ALWAYS be reopened. I'm going to play devil's advocate here for a second.
Is that $200/month really worth pursuing? You know your ex better than we do. Is being forced into paying that extra amount going to lead to issues or with him trying to dodge paying? If you can get him to agree to an amicable amount, and therefore get him to pony it up willingly, it could very well be worthwhile for you to agree to a lower amount, at least initially.
I suggest the following for your consideration:
1. that you agree to the lower amount for a preset period of time (say 6 month to a year) to "allow him to get his financial situation in order".
2. That you ALSO include the fact that this is a temporary reduction, and effective July 1, 2013, and every year thereafter, that CS is adjusted annually, and calculated based on the CS tables.
Alternately, would maybe doing something different with that $200/month be easier for him to swallow? You could always (again for a short period of time) agree to the lower amount, with the stipulation that he deposit the $200 difference into an RESP for the child instead and provide periodic proof of those deposits.
My point is, IF you pursue things through the courts, the table amounts are what he will pay. However, you can always agree to a lower amount if you want to, and other factors considered it may be worthwhile to do so to keep things amicable. You DO have other choices with respect to those funds, that may make it more palatable to him.
How old is the child? Is there anything the child enjoys doing/etc that you can perhaps get him to pick up the full cost on in exchange? (Ie. Hockey, a cell phone, car insurance, etc?) Those are some examples of things that can cost a fair bit, and if he's paying it directly and can see that it's FOR the child, it might be an easier pill to swallow.
Get creative.