As far as I know, K800 is DB2020, so, yes, it can be unlocked, but not for free, after upgrading to CID52 and latest firmware you will have to get some credits online for unlock on services like:
kulankendi.com
sekingserver.com
d-client
davinciteam.com
after unlocking the phone, be sure to Backup your MAIN Firmware befoe attempting anything, before any patching or anything otherwise if somethinng goes wrong and you have to flash the phone again, you will have to pay for unlockcing it again.
DB2020 CID52 unlocking, as far as I knoow is only possible bt Unlock Patch, not permanent.
cya