Heard of them before To be honest I wouldn't buy second hand coilover if there new then fair enough. New Bc coiovers are around 800 . New tein are around 1000/1200 depending .
Most second hand coilovers need a rebuild and And you could be looking at 100/150 each for a rebuild in the uk if they can be rebuilt
Being honest no cos if they were any good they wouldn't be 150 But it's up to you. Hard to tell till there in but the threads rust and you can't adjust them Properly