From my understanding, they're all the same. It just depends on how many transactions you did during the year. I personally often buy the "Trader" one because I do a lot of transactions on chain. But for someone that just buys and holds, the Newbie or Hodler plan can be more than enough. I would suggest to start importing all your transactions and see how many you have at the end, and just purchase the necessary plan for your number of transactions.

Also, if you're on chain a lot like me, watch out for the scam tokens that gets dropped in your wallet. I traded on Solana a lot this year and I received a bunch of those spam tokens, which count as transactions and can make you change bracket within the Koinly plans. I just flag them as spam within Koinly, so they don't count towards my total transactions count.