Sure, if the cost of the ticket was $25 less than everyone else - but you can bet your boat it won't be.I guess I look at this a different way.
United is letting you check one bag included in the price of your ticket. The second bag they are charging $25 to check. I personally would rather them add this Ala Carte service than add $25 to every ticket.
Last time I flew United they added an extra charge for sitting in an exit row (I forgot how much, but it was a bunch). The exit rows sat empty, and no one was alowed to move into them.