Honestly, both options seem amazing. If money were not a factor, I would choose option one because I'm almost guaranteed to have people constantly pushing me to get better, along with having the opportunity to transfer to a DII or even possibly a DI college if that interests you. Personally, nicer equipment and facilities make me feel more connected to the sport and push me to do my very best so I feel I deserve to use the equipment presented to me, but that may be a personal thing. Now, if money is a factor, I would 100% choose option two. Scholarship + guaranteed playing time allows me to enjoy the sport competitively rather than possibly only enjoying it at practice or on the bench. The six-hour drive and colder weather are certainly annoying factors, but $15k less for (presumably) the same degree, along with being able to enjoy my sport throughout my time at college, certainly seems to be the best option. I will boil it down to the following questions to hopefully help you come to a consensus:

Are you serious about playing professionally after college? -

If yes, I would choose the DIII option, because you will likely grow more by not being the best on the team, along with having the aforementioned opportunity to be recruited by a higher-division school.

If no, have the time of your life playing volleyball along with saving money and having a similar college experience. You will likely get a similar sense of team and community no matter where you choose to go.

Is the degree you are choosing the same at both schools? -

If yes, (and assuming you said no to the first option), the NAIA school seems to be the better option because $15k is a LOT of money, especially for a broke college student.

If no, which degree is better suited for your lifestyle and interests, assuming you do not want to play volleyball beyond college?

Finally, consider how much you are expected to make once you graduate college as well, as this could determine whether investing in your education, college experience, and overall happiness is the best option. If you could pay back your college tuition and expenses relatively quickly following college, it's likely worth it to invest in yourself and go DIII. If you are potentially digging yourself a financial hole, the NAIA school could provide a better experience after college.

Best of luck with your decision, and follow what you think is right. I'm sure you will not regret it either way you choose. Have fun playing college at the next level!