Scope is everything with the Lunar Series — decide what "complete" means to you before buying your first coin, because the series spans three parallel 12-animal cycles and an undefined goal is how this collection gets expensive fast.
The simplest, cheapest starting point is a single Series III coin (the current, ongoing cycle) in a size that fits your budget — this gets you into the program without committing to a specific scope yet. If you want to sample the whole program's history cheaply, buy one coin of the same animal across all three series instead.
Series I coins cost meaningfully more than Series II or III of the same animal and size, due to lower original mintages — budget for Series I as a later, deliberate upgrade rather than a starting point. Sizes range enormously (1/20 oz to 1 kilo), so price per coin varies more within this single series than within almost any other on this list.
The Perth Mint sells directly, and most major bullion dealers carry current-series Lunar coins. Older Series I coins are more of a specialist purchase — look for a dealer with specific experience in Perth Mint products for those.
Log it the moment you buy it — cost basis, photos, and today's value in one place, free to start.
Start tracking freeSeries III, the current cycle — it's the most available and reasonably priced. Series I is scarcer and pricier, better approached once you know your collecting goals.
No — that's a personal choice. Many collectors complete a single series' 12 animals, or collect one specific animal across all three series, rather than the full 36-coin cross-series set.