There is a “buy 2 get 1 free” promo going on for some stuff from Anycubic.  Can choose any three things from link and cheapest one will be free.

Some have coupons available as well, so make sure to click on product and add from that page and not directly from this promo page or you won’t see them.

If you see one of these go on a lightning deal, they’ll be cheaper but likely will only be able to add one at that price.