The page size GarageSale uses for downloading listings states is unrelated to the page size you are using on the eBay webpage.
Right now, GarageSale downloads listing states in chunks of 50 listings per page. If you guys want to experiment with that value, here is a version that allows for that:
In this version, you can change the page size to 200, the maximum value allowed by eBay, using this command in the terminal:
defaults write com.iwascoding.garagesale7 getSellerListPageSize -int 200
Please restart GarageSale after having changed the page size with the terminal.
It would be interesting to know how much a bigger page size does speed up the overall process for you. So, if you could time the process for page size of 50 and 200 with a stop watch, please share your measurements. (If that process is too long, you could measure the time for downloading 10 pages with each page size and extrapolate from there).
Keep in mind that we intentionally set the default value of 50 to prevent any beach balling when GarageSale is processing the data. This could be an issue again when you quadruple the amount of data GarageSale has to chew in one go.