Depends a lot on the local market, working ones in good condition seem to go for around $50 here, no idea about the market in Brazil. Shipping a CRT monitor is expensive and proper packing is difficult so it's not normally economical. I suspect prices will go up over time as supplies get scarce. Right now tube monitors are similar to the way tube audio was in the 70s, a lot of it you couldn't give away, even the high end stuff was cheap. It was common as dirt and nobody wanted it, then it was almost all gone and now any of it costs a fortune.
