Wendy's tiny burgers vs White Castle?

Picked up a junior hamburger the other day. $1.99 here in the Milwaukee area! (The JBC is $3.29.) Before I ate it, I grabbed a ruler and measured the patty -- it was 2.5" x 2.5". (Lip balm there for scale.) Decent tiny burger for that price these days, I thought!

Anyway, I was wondering -- how does this compare, in size and price, to a plain White Castle burger these days?