X-VPN is quite cheap (especially, the annual plan), I hope Tachyon will remain cheap too.

Is it possible to pay with cryptocurrencies for X-VPN now? Will it be possible to pay with other cryptos (like Bitcoin, Ether) for Tachyon?

There are the best cryptocurrencies to pay with VPN: https://www.vpnmentor.com/blog/best-vpns-buy-bitcoin-crypto/ and I don't see X-VPN in this list.

Do you mean the best VPNs to buy with cryptos? Well, you can pay for X-VPN with BTC, BCH or ETH now

X-VPN has only 50 supported countries, hope there will be 100+ with Tachyon protocol.

Agreed, VPN addresses from 50 countries only it's not serious. But for the start it's OK.