Using my own location as an example, right now it would cost $1155 to get an adult and a 10 year old child to Nationals. For a single adult, $578. So a flight difference of $577 (go figure). Now lets add on, say, $120 for food for the adult. So for my hypothetical Senior player to get to Nationals, it's costing them an extra $700ish. Take out the stipend, and it's still costing the Senior $200 more to be able to play in Nationals than it does for a Master who goes by themselves.
Which age group is getting discriminated against? I would say it's actually the Juniors and Seniors.