I'm a bit late to this one, but might as well throw my two cents out here.
It's been several years since I took MTX, but I was able to get it through a regular pharmacy no problem. Like jecoll said, a separate prescription for needles is required. Like rrhood, I was able to get insulin needles - the smallest needles available. I don't know if this is standard with MTX injections or not.
I did do the injections myself. I went into the hospital for the first one, and a nurse showed me how. After that it was all on me.
I believe I got either one or two vials at a time and each vial contained two doses. The medication doesn't require refrigeration, but do check the expiration dates. I got several vials that were close to expiring (although they had not already) so I kept a close eye on it.
I would suggest that someone on MTX make an effort to keep spare needles on hand. At times, I'd come across dull needles that didn't break the skin easily - and at times, if I had to reinsert the needle into the vial for more medication after releasing the air bubbles, the needle could become dull. Rather than forcing it, you can remove the needle from the syringe and replace it with a different one. Much easier.