Cheapest is using bittrex to buy hive directly (.3% fee). Send the hive to your splinterlands account. Deposit the hive (1% fee) via one of the many Hive DEXs and then use it to swap the newly acquired swap.hive to DEC or SPS (~.01% fee).

Thanks for helping. But it seems Bittrex currently can't withdraw HIVE. It says Deposits and withdrawals are temporarily offline.
Do you know how often it happens and how long would it take to recover?

This is because Hive itself is having issues. Unfortunately no matter what method you take you'll run into this. That said, it should clear up over the next day or two. This doesn't happen often.

Hello, @johnny1229

This is @fionasfavourites from the @ocd (Original Content Decentralized) curation team. We noticed you shared your first post here on Hive - congratulations and welcome! It would also be awesome if you could do an introduction post, so our community can get to know you better. For an example of what an intro post is like, you can check out this one by my friend & curation team member - Keeping Up With the Buzz – My Introduction to the Hive Community.

Speaking of community, we have many different ones here on the blockchain, devoted to all kinds of interests. Here's a link so you can check them all out – Hive Communities.

Also since you're new, you may run into an RC (Resource Credits) error when trying to comment/post because you don't yet have enough Hive in your account yet. For assistance with a temporary delegation to get you started, be sure to check out the Gift Giver site.

Also, as this the hive can be quite confusing, the newly launched Newbies Guide is a growing repository of useful – easy to understand – posts about how the Hive ecosystem works.

For now, @lovesniper will follow your account and we are looking forward to seeing your intro post. Also, you are welcome to tag me (@fionasfavourites) and please mention @lovesniper in your intro post in order for us to be notified, so we can consider your post for OCD curation. Feel free to hop into the OCD Discord server if you have any questions!