It is okay to buy a used Programmable logic controller (PLC) so long as there is no physical damage. However, do note that because it is used, there is always a chance that it could be damaged.
yes getting a used plc is not a bad option because these programmable controllers never get out of order soon but before buying first checkout all the keys and its connector i always see that its connector is too much complicated and you can not change it so keep checking and then get it