It looks like the yellow/magenta head can be recovered and usable but that black is going to be a problem which affects the cyan as they share the same head on that machine. It all depends on what quality you are willing to let jobs leave your shop. The black in this test print will most likely leave black spray on the edges of your prints and anywhere there is white space. Any black lines will not be crisp as well. You could try doing head soaks, powerful cleanings and even flush the head but there is no guarantee it will help. In any machine the alignments should be done as perfectly as possible so you would definitely want to check them out and tweak them as necessary but that black head is going to cause you headaches. I would find out when the maintenance parts were changed last from the current owner. Based on the test print I am sure you will need new cap tops and wipers. Your pump may be clogged as well.
Get one of your files printed on that machine before you buy it. A lot of the time you can get a test print out of a head but when you try to print with it, it can leave streaks across the print that don't show up in a standard nozzle check. If that is the case, you will end up needing a head for sure.
