Short answer — trusted places to buy authentic luxury fashion in/for Australia:

• International authorized luxury e-tailers that ship to Australia: MyTheresa (AU site) — guaranteed authentic, returns and local shipping options. (MyTheresa.com)
• Multibrand marketplaces that specialise in new designer stock: FARFETCH (global boutiques network; authentic items from boutiques/brands). (apps.apple.com)
• Department stores/authorized Aussie retailers with designer sections: David Jones and Myer (both sell brand-new, authorised designer stock) — check each product for “sold by”/brand-authorisation on listings. (general industry practice).
• Reputable pre‑owned/resale platforms with onsite authentication: eBay Australia (Authenticity Guarantee for eligible luxury handbags/wallets) and Vestiaire Collective / TheRealReal (authentication processes but read each platform’s claim period and return policy). (ebayinc.com)
• Australian luxury boutiques and curated sellers (examples): established local boutiques such as Cosette (large Australian luxury seller — note it has faced public scrutiny but was cleared in a Fair Trading investigation; still check provenance and policies). (dailytelegraph.com.au)

Key things to check on any site before buying

• “Authenticity guarantee” or onsite professional authentication process (who does the checks, where they happen). (ebayinc.com)
• Clear returns policy and reasonable reporting window for authenticity problems (many resale sites require you report issues within a short time). (theguardian.com)
• Seller/stock provenance — “sold by [brand]” or fulfilled by the platform vs third‑party marketplace sellers. (MyTheresa.com)
• Reviews/ratings on Australian consumer sites (ProductReview, Trustpilot) and recent news about the seller — some well‑known luxury platforms can have mixed local experiences with shipping or service. (productreview.com.au)

Quick guidance for risk reduction

• Prefer authorised retailers or major luxury e‑tailers (MyTheresa, Net‑A‑Porter, Farfetch) for new items. (MyTheresa.com)
• For pre‑owned, choose listings with an explicit authentication badge (eBay AU Authenticity Guarantee, verified items on Vestiaire/TheRealReal) and keep all paperwork/photos. (ebayinc.com)
• Keep documentation (receipts, photos, serial numbers) and act quickly if you suspect a problem — Australian Consumer Law gives remedies for products that are not as described. (theguardian.com)

If you want, I can:

• Make a short, current list of specific Australian websites (links) ranked for authenticity and service, or
• Check a particular store or listing you’re considering and summarise whether it’s reputable and what to watch for.

Which would you prefer?