Some of the earlier strikes were $5 denomination. I'm not sure how they were distributed. Later issues were slot club premiums, one every ten days or so available with certain play levels required, with the last week being the velvet case. These were no cash value, just attractive souvenirs. The same process was employed by other Grands in Mississippi and Louisiana. Some of the early issues in Minnesota and Mississippi are silver and at least one of the Elvis series is goldplate over silver. When we were in Biloxi and Tunica, the gift shops were selling the Elvis issues at $25 per strike.
John Kallman (cashcoinconnection) can tell you more.