I'm fairly certain that these prices are higher than what you'd find being pitched by the developer, to say nothing of the fact that both Westgate Lakes and Marriott Cypress Harbor are Interval Internal affiliated properties, not whatever "Resorts Condominiums" is supposed to be.
This company charges $98 for "lifetime membership" and $398 to list your timeshare for sale. I'd like to know how long the Westgate Lakes property for $30,000 has been listed.
Yet another example of timeshare owners being led astray. There are legitimate secondary market platforms out there. No, I'm not one of them, No, I don't sell timeshare. However, I'll be happy to point you in the right direction.
Alas, this "membership based company" isn't the way to go.