I'd do both. Announce in a separate post and use the "master list" link as a "for more stuff".

Like this:
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FOR SALE - purple UniKittyCat like new. Comes with teleporter and warp drive. Dilithium crystals included.
Can say "meow'" in 10 ancient languages and 30 modern languages. Offer two cans of moist cat food each day for maximum satisfaction. Do not butter. Price: $3.14159 or best offer. Postage: 4,500 quatloos for US.

I have other items for sale as well -- check them out at my link here: http:yaddayaddayadda.commmm

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I'll def construct something ty for idea