When the landlord gets your opening brief, he MIGHT file a responsive brief. Oftne they don't because they know they'll lose on appeal and they don't want to invest any more money in it.
If the landlord does file a responsive brief, we need to see if he raises any issues that you need to address in a Reply. Reviewing that brief often requires additional research as well as the time reading the brief and evaluating the arguments, and then reporting to you.
Given the unknown nature of your appeal issues, the $200 posting price on this is the MINUMIUM for reviewing and analyzing the Responsive Brief. Depending on the number, complexity, and record on the various issues you raised on appeal, and any new ones the landlord raises in Response, this amount can increase, and you will be advised as to the amount needed. You can then decide if you want to file a Reply Brief, responding to the landlord's Respondent's Brief.