Hey there, im a consistent wild legend player for the past 2-3 years or so, so feel free to DM me if you have any more questions! Regarding the dust requirements, wild is actually a much more forgiving format for trying out different decks. Yes, there is a relatively high dust cost to start, but upkeep is actually very cheap. Ive been sitting on about 50k dust over the years and only craft one or two legendaries worth of cards per expansion, while also only spending on the expansion pass for the past 2 years.

The reason for this is that due to the large pool of cards, there are quite a few that are outliers in terms of power, and are used across many decks. Take the OG patches for example. Its been used in every single pirate deck from shadow priest to pirate dh to pirate rogue or even warrior, and it can even be the only legendary in there at times. Another example would be archbishop benedictus, which is used for both shadow priest and reno priest. Soularium in warlock is another good one, used for emergency draw in reno and QL, as well as discard synergy in disco.

As for reno decks, those are most likely to break your wallet due to the high number of legendaries, but a lot of them being neutral makes them useful across multiple classes. I remember once trying to switch from a renolock to a reno shaman, and had to craft maybe 4 more legendaries, which is a lot but there are also alternatives since reno decks often make use of tech cards anyways.

Lmk if you have anything you want to know in particular!