In 2018 delta bought 20 crj 900 for $961 million. Each plane cost $48 million. Used price would be half of that. So yeah, that is a really cheap price.

the crj700s had very few maintenance issues.

According to JO.

As someone who operated them out of IAD I can say they were well maintained and reliable.

I flew thousands of hrs in the 900 and 700 at mesa. The 700s were very well maintained I would spit ball and say they operated with 80% less MELS than the 900s.