is there any rule of thumb about the premium for this designation on graded coins? Say an 1885 P MS 65 is priced at around $150-165. What would be a typical price for a DMPL 1885 P MS64? Rough guess I'm asking here.....would $500 be crazy?
Not sure about a thumb rule, but Numismedia website would give you some numbers (probably too high, but tending to counteract each other) that you could ratio to at least get an idea about the premium for the DMPL.
it might be a good price. not sure. if I were you I would private message Amanda Varner on the prices these DMPL get. her/their coin shop gets/sells a lot of these DMPL slabbed coins. she could tell you what these coins prices get. Amanda's forum profile link: https://www.cointalk.com/members/amanda-varner.59002/
PCGS.com has a price guide for slabbed coins under the "resources" tab. It has prices for each year/mm for MS, MS+, PL, PL+, DMPL, and DMPL+. That should give you the most accurate "book" value...now as far as premium over that based on eye appeal, that is up to you sir. http://www.pcgs.com/Prices/PriceGuideDetail.aspx?MS=1&PR=1&SP=1&c=744&title=Morgan+Dollar
Ebay listings for DMPL MS 64 Morgans ... link: http://www.ebay.com/sch/i.html?_odkw=DMPL&_osacat=39464&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.XDMPL MS 64&_nkw=DMPL MS 64&_sacat=39464you should probably check the completed auctions for a more accurate feel of the market. completed listings for MS 64 DMPL Morgans... link: http://www.ebay.com/sch/i.html?_sacat=39464you&_from=R40&_nkw=DMPL+MS+64&LH_Complete=1&rt=nc
Heres a good site for fair market value http://www.numismedia.com/fmv/pricesms/mordlrdm/prices61.shtml