Without knowing what your product is or what your market is, my default comment is that you could probably change it to 38, 98, and 198 and increase total reven

Without knowing what your product is or what your market is, my default comment is that you could probably change it to 38, 98, and 198 and increase total revenue while ridding yourself of a small number of customers that eat up a lot of customer service time. The 6-month pricing seems unnecessarily manipulative.