I go to a private pharmacy associated with the clinic I go to for HRT. I pay less than $80 for 24 syringes, 24 drawing needles, and a 10ml vial of T. I have a regular weekly dose and the vial I get lasts me around 5 months. I've never actually tracked from start to finish, but that is my estimate. I always have syringes left over at the end, so I know it's not a full 6 months. It may last longer now, as I need to get my dose adjusted post-hysterectomy.
If you have insurance, call them and see what they'll pay for. Some will only pay for a 1 month supply, which is a very small vial and it's tough to get the last dose out. See if you can get them to cover a larger 10ml vial. If not, download the GoodRx app and see which pharmacy near you is cheapest. Also be aware that some pharmacies don't carry larger vials and will need to order it in advance for you, so calling ahead to see if they have the size you need may be helpful.
As far as needle anxiety, I had a ton of it. I started on gel and only switched to injections when the price went up too much for me to afford it. Initially it would take me an hour to do everything. My advice would be to get into a routine as early as possible and do the same thing every time. Find some kind of activity that relaxes you. For me, I would listen to music. I'd get one song to get all my supplies laid out and ready to go, then I'd get another song to do the injection. It helped to have something to limit the amount of time I was taking. I also made a point initially to do my shot in the morning, so that it couldn't take too long or I'll have wasted half the day and been late for other things. And even though it may not be your first inclination, I recommend doing your shot weekly not only to get used to the hormones, but also to get used to the injection process. Doing it biweekly puts it more out of sight, out of mind, and you may find that the infrequency causes greater anxiety because it takes you longer to get used to it.
Also, for shots and pain: ice the area before and after your injection, massage the whole area after your injection, and consider taking an OTC pain killer.
It shouldn't take you longer to see changes if your dose is correct. My biweekly dose would be the same as two of my weekly doses. You might experience some moodiness in the days leading up to your shot, but as far as changes and masculinization, frequency should play no part as long as the dose is the same.
Just out of curiosity, have you found an endocrinologist or someone to prescribe your T? Just asking because people sometimes get confused about what the referral letter from their therapist gets them.