Credits to NamelessHero27 for this suggestion in Discord:
"Put regular surf, without mount and only with hm03 is 0%. It's like just walking on waters. Put regular (not shiny) mount at 20% more speed. This means cheaper than now. THis will be Surf Mounts entry level, will be bougth by people new, in story, with small money. Economy will move. Put shiny mount and jet skii 50% (that should be as it was jetskii till 3 days ago). Jetskii and shiny mounts at same speed willl move economy because people will buy and trade fav mounts and not only jetskii to go fast. I repeat, this 50% should be what jetskii was till 3 days ago. Put Kyogree mount 70% faster, pvp coins only, not tradable, more expensive. Exclusive and high level fast mount, reward for pvp player. I think like this, economy will move (nobody will just be "forced" to have only the jetskii), complain will go away, and well I think everybody got their goal
Greetings"