How many releases will Johnnie Walker have for Ghost and Rare?

Jeff_Misiaszek

I've not been able to find any information on how many releases Johnnie Walker will eventually have for the Blue Label Ghost and Rare series.  For example, they came out with Brora in 2017, Port Ellen in 2018, and then Glenury Royal in 2019.  This year they released the Pittyvaich version.  Does anyone know how many versions they will have when they are finally done with these releases?  Maybe they don't even know and will just keep producing new ones based on their stock and commercial success?

The reason I ask, and I'd be interested in all your feedback, is that I have a bottle of each of the first three releases above, and would like to collect the whole collection and eventually sell it for a profit.  Does anyone think that is a good idea?  Like will these bottles appreciate over time? And will having the entire series release be better?

My point is if they are having like 10 versions, I probably won't be able to keep affording to buy these bottles (lowest price I've paid is $300/bottle, and that's the LOWEST).  But if they will stop at this fourth release, or maybe have one more, I can finish up my collection.  Thanks for any information anyone has!