I haven't seen DC or Marvel publish 99 cent comic books for a looooong time (unless they are digital first books). Today's Justice League United #0 was $3.99. At least Original Sin #0 was 33 pages long for $4.99. It was basically a double sized issue of Nova. Any current Sam Alexander Nova fans will enjoy this Original Sin "prologue." I did.
Now after I typed this, I remember Marvel republishing the first issue of Strikeforce Morituri for 99 cents back in 2012. And other comic companies have published first issues for a $1.00. Aspen Comics had a 10 for 10 initiative last year where the first issues for books like Fathom and Jirni were only $1.00