said by LLigetfa:
Around here the cable company offers packages with one gig caps. 50 gigs these days is paltry. 250 gig caps are common.
It appears the OP is using Cox HSI. Cox has 5 different tiers of HSI service and subsequently 5 different monthly prices depending on the market. Some markets may not offer all five tiers. Depending on the tier your subscribed to the cap can vary quite a bit.
It simply comes down to what a person can or wants to spend on internet access with Cox.
FWIW I am in the preferred tier for my Cox HSI. My wife and I are pretty light users of our service and we never come close to using up the quota...