If you are arriving two days prior to the convention start, it may make more economic sense to just purchase a multi-day base (or hopper ticket). I think the prices for an After 2:00 are around $60 and the After 4:00 around $50.
If you need a two full day ticket for the days before your convention starts it is $162. However the third day adds $62 more, the 4th day adds $8, and any additional days are only $5 each.
So if you will be doing the two days before your convention plus at least two afternoons or evenings during the convention it is much less expensive to just get a regular MYW ticket.