Finders Keepers Floral Cap Sleeve Mini Dress

I recently bought this dress but it fits more like a size 8-10, which was much more spacious than I expected as I bought it under the impression that it'd be a size small as it was originally listed by another posher. I've included photos for proof that there are no size labels. I am a size 6 and this has extra space for me, but if you're a size 8-10, it should fit you better. This is a unique Australian-designed dress from the brand Finders Keepers; I haven't found this one in a smaller size yet given its uniqueness. It's a midi dress for petites but a mini otherwise. Great for work, brunch, etc. I bought it for $29.61 overall and couldn't use it as it wasn't bodycon for me (size 6 currently) so I'm looking to sell it and have 30 after Poshmark; I hope this sheds some light as to why the price is as is.