Should I attempt to purchase my authorized prior service medals before shipping to basic training for the second time?

Yes, you can wear them. We had a guy graduate a second time wearing 12 awards, a SSI-FWTS and stripes. Awkward for him, with everyone wondering wtf he was doing there, but certainly doable. He was a SGT who got out 10 years ago and signed up again.

If you earned medals in a prior term of service they should be in your paperwork listed or in whatever the electronic equivalent record is these days. If your going through BCT again the NCO's will either obtain the medals for you via their internal supply system or allow you to purchase from a location on post. Of course they are going to want to see proof that your entitled to wear them. Nobody expects you to bring them with you especially if you had a break in service. The NDM and GWOT should be readily available at BCT via the cadre, the reserve medal they can easily obtain for you via supply. I never spent money for medals in my long ago ARNG to RA transfer. The Army issued them to me again.

SPC Josh Tharp I would want to have them for basic and I believe you are allowed to wear them. You've earned them, they are yours. But I'm sure people who are more in the know than I am will comment as Ive been retired for too long. Good luck.