United re-introduced their annual “subscription” services: economy plus subscription and baggage subscription. The baggage subscription is simply a euphemism for bag fees in which they collect a $349 annual subscription instead of piecemeal for $25 each time you fly.
The $349 does allow you and up to eight companions traveling on the same reservation to check up to two bags each per flight for free. (Excluding overweight bags). So if you are traveling with your eight person Korfball team, it might be worthwhile.
Otherwise, if you’re not traveling in a group or carrying a lot of equipment, it’s hard to recommend this program unless you know you have a good deal of travel in advance. If you have that much travel coming up, it seems like you should be able to qualify for elite status and get at least your first bag checked free through a United challenge.
In addition to the baggage subscription United is offering an Economy Plus subscription providing access to seats in Economy Plus with more legroom for $499 annually. Since Silver members can only select Economy Plus seats at check-in time, this might have some value for you. It all depends on the duration of the typical flights you take and how much the extra legroom means to you.