The anvil was only ever worthwhile in the early parts of the island. However, at that time it was much better to spend LCs on the Golden Chilli, Paladin and Bard. For those with Facebook friends and access to friendship essence (not me), it was always possible to re-roll when making crafted items.
The Golden Cauldron becomes worthwhile in the early parts of the caves, when you start needing potions and veggie cakes to help complete levels. I got the Golden Cauldron probably half way through the caves, when I needed more healing. If you use lots of healing potions, fruit cakes and veggie cakes to complete caves, then I think it is worthwhile. Until you can complete SRC quickly to gain snoutlings, farming for ingredients and crafting potions etc is a good option.
I used a lot more potions in caves 11, 12 and 13. But I was level 41 with mastery in the range 6-8. If you are at a higher level with similar mastery (and good weapons) I don’t know that you would need as many healing potions and veggie cakes. I am working on the last cave (just taking my time since I don’t expect anything new for some time) and only farm for ingredients occasionally. I haven’t actually needed much so far in the 2 new caves, but that will be because I am at a higher level with max ranks.
I could also say that it can get boring just farming snoutlings at SRC. Farming for ingredients is something else you can concentrate on. But at this stage, particularly if you compete in the arena, it is probably more time effective to farm for snoutlings and buy potions.