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DCX just listed the old FA SMC 31mm f1.8 Ltd at $899. They are participating in the current 15/17% off on eBay Australia, so that comes down to $746.17.
PENTAX SMC FA 31MM F/1.8 AL LIMITED LENS (SILVER) (20280) 27075051133 | eBay
I don't think I've seen it this low. In fact, I don't think I've seen a used copy go this low on eBay. I've already got the 41 and 77, so grabbed this even though I'm not that fussed on silver (though I think it will look cool on my MX)!
They have plenty of other lenses of course....worth a browse.