Verizon no longer offers any unlimited wireless data plans, as of March 2015. The company formerly offered such plans but ended them in 2012. The only users that have access to unlimited data for a flat fee are those with accounts that are grandfathered in before that time.
Verizon's largest current monthly wireless data allotment for phones is 100 gigabytes under their More Everything plan, for which they ask a base price of $750 a month. Prepaid MiFi hotspot plans can only go up to 10 gigabytes for $90 a month. Additional gigabytes can be used under any plan, but there is an added fee of $10 or $15 for each gigabyte for most plans.
Legacy customers who had unlimited data plans prior to their shutdown in 2012 can still retain those plans if they have kept them continuously active and do not enter a new contract with Verizon. Verizon previously attempted to force customers out of these plans in 2012, but was legally unable to do so. They then announced plans to throttle the connection speeds of legacy users in 2014, but walked them back when the FCC voiced its displeasure with the idea. Some legacy unlimited data plans cost as little as $30 per month.