Under normal circumstances, I would have brushed this aside but in this case a post is overdue and necessary. D-city been largely automated by its own. Nothing much to do but just to vote, buy, sell and trade. Daily rewards collection and the occasional discoveries very much automated. However, when one does manage it once awhile, it could be quite addictive especially when holding couple of days accumulated SIM.
On normal mornings, the usual haul could be technology cards or background no more than tier-3 until today! In fact the discovery was more than a day ago from this post. Guess the repetitive, ritualistic, checking of daily haul went amiss without notice sometimes. Similar to a situation when I doubt myself of locking my car when I have entered the building, as the action was subconsciously carried out.
Yeh me! Joebabana found a Mining-ETH technology card. Some facts about this tech card Mining-ETH. So far there are around 31 minted according to Rafalski HiveData Stats
Historically sold for;
and currently listed in the market for around USD ~49 
Now I'll need to consider the opportunity to sell or let it sit to accumulate SIM. What should I do?
I think the takeaway here is, DCity Discord channel enriches my experience and hope it does for you too. Come over and join the game. There is always room for new endeavors and opportunity.
In case you've never heard of D-City, here is the game site https://dcity.io/.
Come Join Us at Discord for a better gameplay experience
Here is an award winning tutorial for Beginners Guide
or for the more seasoned/return player may check out 2nd Edition Card Play Guide
Happy Halloween everyone!
If you are happy with how much extra you are getting, keep it. Otherwise you could try sell it to get other cards and boost your city.
I am holding mine due to SIM increase.
That's a valid point Mr.President. I wonder would the mining-BTC card overrides this or compliments mining-eth?
The higher % mining card gets used. So BTC mining card would be used instead of ETH. Then you sell the lower one, or if you have another city with decent income, you could send it there.