Ya Chuck I think I paid $99 to upgrade from X3 to Professional when they first came out with the new system.
So the OP probably did the same.
I later took the bait and upgraded to Plat for I think $160. Still cheaper than the full price by a lot.
The beauty is I still have X3 which if all else fails was a great version.
And I still get to keep Professional which I installed to unimportant machines just to open when helping on the forum here. I sometimes muck about with a midi file but it's next to useless without a proper audio interface. The other bonus was I got 1 add pack for AD with Pro and and other 2 with Plat.. So taking the upgrade path has huge perks as far as I can see. I think I saved about $200 off full price.
So Todd your sittin' pretty.. You get to use Professional for as long as you have a computer that will run it. You'll get updates for a year, not a lifetime and they will make you juicy offers to upgrade to Plat.