From the Realflight website:

If you purchased G3 or G3.5 on or after May 1, 2007, choose one of the following rebates:

$100 Merchandise Certificate OR $50 Cash (option a)

If you request Option A, you must provide a dated cash register receipt showing that you bought your RealFlight
G3 or G3.5 on or after May 1, 2007. If you do not have the receipt, you must request Option B. If you request
Option A and do not provide the dated cash register receipt, you will automatically receive Option B.

If you purchased G3 or G3.5 before May 1, 2007, or do not have a dated cash register receipt showing purchase on or after
May 1, 2007, choose one of the following rebates:

$75 Merchandise Certificate OR $30 Cash (option b)


http://www.realflight.com/promos/rf-g4-rebate-form.pdf

Rob