Since there is next to zero liquidity already since it really isn't listed on any exchange and that it's actually abandoned like you've said, unfortunately chances are, your PoSTokens are worth zero or almost zero.
https://coinmarketcap.com/currencies/postoken/
Yes. I'm aware. It's been a long time since trading for PoSToken stopped probably because the developer abandoned it. What I loved about PoSToken the most, is the ability to "stake" tokens right from the Ethereum blockchain. It could've been the future of ERC-20 tokens on ETH, as they adopt features similar to those on PoS blockchain networks. I've also seen ERC tokens that are mineable (like 0xBitcoin and KIWI), bringing a whole new world of possibilities on Ethereum.
I guess that abandoned tokens can still be traded on decentralized exchanges or in-person, if there's enough demand for it. I've stumbled across an exchange called "Uniswap" which allows anyone to list an ETH token. There's also McFeeDEX which allows you to do the same. The only issue would be liquidity, as decentralized exchanges are not well known or used by serious traders in the crypto space. I'd definitely love to stake more PoSTokens just for fun, by buying more via a DEX or an OTC site. Maybe someday, a developer becomes interested in building upon PoSToken to make a new and improved version of it. I believe that the future of crypto lies on stakeable or mineable tokens right on the Ethereum blockchain without the need to start your own blockchain network from scratch.
Reply above of mine was right, they have totally abandoned this project and now it becomes worthless or a zero value in the market and there's nothing you can do on selling and buying with this.
That's very disappointing. Besides the project's HYIP scheme, the core token itself had a very promising concept. It was the first-ever token on the ETH blockchain with PoS (sort of). Anyone could "mint" new tokens on ETH just as they would with ordinary PoS cryptocurrencies like Peercoin and Blackcoin. Since there's no exchange available for PoSToken, my options for staking this token are limited. I doubt there's still demand for PoS-based tokens right on the ETH blockchain. I've also seen a lack of interest from everyday people into ETH mineable tokens like 0xBitcoin and KIWI. At least, the idea/concept is there. Maybe in the future, developers would make PoS and PoW tokens on ETH a hit. In the meantime, I'll stick with other popular tokens on the Ethereum blockchain with better returns. My wallet still has a bag of PoSToken, waiting there to be sold if it ever comes alive in the future.