Hey adobbing, Melia's ticker symbol is MEL, if I am not mistaken. You can check more on their performance here: https://www.bloomberg.com/quote/MEL:SM
Currently 1 share cost 12.12 euros, which means 1,000 shares will cost 12,200 euros.
As per this page, in order to get Gold status in MeliaRewards as a shareholder, one need to hold a minimum of 1,000 shares for one year.
I also noticed interesting discrepancy between lists of elite benefits listed on MeliaRewards page and shareholders' page: on the page above it says that Gold members will receive welcome amenity, 11am check-in as well as 50% discount on upgrade. I wonder if this are new additions or old page
Current list of elite benefits can be seen here.