In your case you should be able to purchase a maintenance agreement for 1/2 the cost of an upgrade.
I asked TechSmith about this before Camtasia 9 was released.I was told that if you were to purchase Camtasia 8.You had 6 months to purchase a Maintenance Agreement at 1/2 the cost of an upgrade. That would give you the maintenance agreement for a period of 1 year.It also entitles you to a free upgrade to Camtasia 9. I couldn't find a link for purchasing that agreement so you may need to contact sales on Monday to purchase one. That's probably not what you were hoping for but it's an option and better than paying $99