There seems to be a second, shorter, mini eshop sale on top of the weekly one launched on Thursdays. Nowhere seems to be reporting it and I'm really surprised it hasnt been mentioned on here. I only knew because of the Switch news page. It's being promoted as a 'gaming on the go' sale and runs between 27th October and 1st November.
There a whole of bunch of well-known titles discounted from huge series entries like Street Fighter Collection, RE Revelations 2 and Monster Hunter Generations Ultimate to top indie games such as Owlboy, INSIDE, LIMBO, Severed, Axiom Verge, The Gardens Between and Blossom Tales.
I just picked up RIVE at 50% off and Golf Story, which is 33% off but I used my 400ish gold coins to pay less than a fiver.
EDIT: Seems it has been discussed on here and reported on the two websites I checked, Nintendo.co.uk and NintendoLife. I have no idea how I missed this. Maybe my focus has been on Red Dead Redemption 2 too much. Glad I caught it in time and didn't miss out on some bargains.