First off, I am no expert. With that said, I purchased a Epson artisan 1430 off craigslist for $125 last year. The person I bought it from had used it for graphic art design and then ended up getting a different printer at some point. She said it had been sitting for months without being used, but said it worked fine. She seemed honest and the price was good so I purchased it.
When I got home and performed a nozzle check. I found all the print head to be completely clogged up with no ink coming out. I purchased some empty refillable cartridges that have reset chips in them online. Filled them with a mixture of 1 part ammonia to 10 parts distilled water. Ran a few head cleaning, then let it rest for an hour, more head cleanings, then let it rest for an hour, and nozzle checks in between etc. Are spending an afternoon doing this, everything got cleaned out, and printer worked perfectly. I've been using it for a year now with no issues. So from my experience, even if the print heads are clogged, they can most likely be flushed of again. there are some youtube videos out there on how to clean print heads also.
There are no certainties in life, but if it was me, and the price was right, I would not be afraid to proceed with the purchase if that was the printer I wanted.