When the Club Deck was built in 1990-91, the seats were sold as a debenture in a scheme called the Rangers Bond. The cost of the debenture was approximately £1600 (the guts of 4k in todays money), and for that you got a wee silver plaque on your seat and first dibs at a season ticket for said seat. It was quite an engineering feat, what with it being plonked on top of the listed main stand, but it was wrongly lauded as being a stand in the sky - the stand is only a smidgeon higher (if at all) than the Govan stand opposite.
As a footnote, I think all debenture holders lost the rights to their seats when the club was liquidated in 2012.