Where can I buy runes and Ordinals?

As a cryptocurrency enthusiast, I'm curious about the availability of runes and Ordinals. Could you elaborate on the various avenues where one could potentially acquire these digital assets? Are there any specific exchanges or marketplaces that cater to the trading of runes and Ordinals? Additionally, is there a preferred method for purchasing these, such as using fiat currency, cryptocurrencies, or a combination of both? I'd appreciate any insights you could offer to help me navigate the purchasing process for these unique digital assets.