If you stay in until you retire should you have a degree?

I generally do agree with the sentiments expressed so far.

If you look at what MSG(P) Quick points out - roughly $90k available throughout a career - and what is mentioned by MSG(R) Huffman I find that my thoughts are pretty much there as well.

There is no reason that you cannot have one.  Should you have one?  Probably, but it does depend upon the individual's goals.  Sometimes those goals change through the course of one's career.

Personally, I used to be the NCO that would work the extra shift to allow my Soldiers to go to school.  I felt that with the credit that would be awarded to me as a 15Q, I could always "just do it later."

Fast forward, and all of a sudden, it IS later.  I sat on 90+ hours for years, and I had to get BACK INTO going to school in order to get a degree completed.  Last year, I did just that.  I completed a degree after 22 (and a little bit) years in the Army, I was awarded my Associate's Degree.  

Fact of the matter is that it was not that much work to get it.  I just had to decide that I wanted to do it, and prioritize it.  At this point in time, I'm only a few more classes away from my Bachelor's Degree, and I'm going to finish that as well.

Truth be told, I do wish I had simply gone ahead and gotten it finished earlier but at that time in my life, I simply wasn't prepared to commit the required energy to it. 

I encourage every young Soldier that I have the chance to talk to, to not be exactly like me.  Use a degree plan.  Don't just take stuff that is "fun" to take.  I did that, and it worked out alright, but it would have been much simpler to do (based on available time in my life) when I was younger.  :D