I agree it's a little misleading in the wording, but they are talking from a Sponsor's point of view - if you add up prize money for all Tiers it does in fact come up to 50k. It's not uncommon to list the "Total Purse" in a multi-tiered event.
TC=12, C=10, TL=8, L=6, TM=5.5, M=4, TP=2, P=1.5, Am=1