If I were you, I'd wait because at any time up until 2019, the Perth Mint can produce unlimited numbers of any year of the bullion kilos. When a rush of these kilos come on the market, the prices tend to drop quite a lot as competition drives prices lower.
Collecting the silver proof kilos is a whole different project. They are much, much scarcer and will not be minted past the max set mintage for the year and never beyond the year of that Lunar animal. As of a day or so ago on eBay, I saw a proof silver kilo horses for a tad above $1,500. At the end of 2019, the premiums that collectors and buyers will be paying for the proof kilos clearly will be far greater than what they would be paying for the bullion kilos which could theoretically be minted into the many tens of thousands.... making them rather common for a bullion coin in the 1 kilo size.
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