The Mint Mark cannot be Doubled Die. It is a plated zinc planchet so it probably just DDD - Die Deterioration Doubling. http://www.error-ref.com/die-deterioration-doubling-incuse/
yes to DDD, the mint mark and date show the same doubling which can not occur on a true doubled die in 1988 as the mint mark was hand punched into the die after it was made..
Here's another reference to the 1988 reverse of 89 Lincoln cent: http://doubleddie.com/278743.html Don't know if there's any difference in value as I don't see them listed in any price guides.