Users choose which relay to use. Relays set their own prices, although some may offer services for free. 

 Interesting. How do one get ecashu? 

 Using your lightning sats to mint ecash sats. https://image.nostr.build/61805b646754bcfc514dcd4065cdd99886a0ed01755dbfaef59c70012a230727.jpg  

 Easy. Following.