Miners profitability

[Anynomous]

@DJAYKIND

Obelisk GRN1 Mini it claims to have a 15 day payback

The Obelisk GRN1 was cancelled long time ago, see this forum post:

GRN1 Cancellation Announcement

Due to a lack of interest and funding, Obelisk has had to cancel the GRN1 project. All who purchased the GRN1 directly from Obelisk will be receiving a full refund for their purchase. Refunds will be provided in the form of BTC equal to the USD value of the amount paid at the time of purchase. If credit was used, the credit will be added to the amount refunded. If coupons were used, the coupons will be returned as coupons. Several factors proved to be significant barriers to the GRN1 project. T…

@DJAYKIND

are you presently mining a coin

Yes I mine Grin on RTX 2080 Ti INNO3D and get around 0.76 G/S. I am still waiting to receive the G1 Minin miners from iPollo. As far as I know, the G1 and G1 Mini are the only viable ASICs around.
In general, if something sounds to good to be true, it is. E.g. ROI of 15 days, why would they even sell such a miner and not just use the miners to mine for themselves privately and earn much more than they would get from selling?