Don't buy a printer on Bitcointak, buy it on Craigslist. That makes a targeted attack much less likely.
You should know that most printers have coded tracking dots that prints invisible Machine Identification Codes with time, date and printer serial number on paper, with who knows what else to track what you print.
If you are interested in that subject, maybe you should check that program:
https://github.com/dfd-tud/dedaDeveloped by scientists from Dresden, allows you to detect and modify/remove yellow dots. Or just read a data encoded.
By the way, do you know story of Reality Winner? Yep, dots.