If I were you, I'd not ask for the raise. I'd just quietly look elsewhere for jobs. But I'm risk averse to a fault.
The ideal way to handle this is to decide on a priority list. Do you see yourself working here long term? What do you think about working for a start-up vs a big company? What are the prospects of this start-up?
I'll answer the rest of the question with the assumption that you want to continue working here long term.
Print out the research you've done and bring it to your manager. Decide ahead of time what you are going to ask for, how you propose to earn it. So something like this would be the summary of what you want him to know:
Boss, based on the market value, my worth is $65,000 to $70,000. Here are the ways I've already provided value to the company. As a student I spent x hours providing value here, and 40-x hours learning. Now with the new degree, I estimate spending y hours providing value and 40-y hours learning. (y should be much closer to 40 than x).
I'd also ask you to think about what you're really asking. This is 2x your current salary, so it is very unlikely that your salary will double. You could insert something about how you aren't asking for $70,000, but something closer to 10% - 20% raise of your current salary, depending on how he responds. I wouldn't open with that, simply because you're only asking for average market value.
Option-2: I'd also start interviewing elsewhere just to test out the market. If you can go to your manager with data to back up the argument, even better. That conversation can look like this:
Boss, I love working for this company, here are the ways I've already provided value to the company. I see a future for myself here. Based the recent interviews I've had, my worth is $65,000 to $70,000, and this is half of my current salary. If you were in my shoes, what would you choose?
With the second option I'd be VERY careful about framing the argument.
In addition to the base salary, I'd ask you to think about bonus compensation, stock-options (remember most start-ups fail) or PTOs, or another option that doesn't cost $$ to the company, but adds value to you.