I'm so sorry that you're disappointed about your big not being there for you during your initiation!
Lucky for me my big was there but her and I never really had a close bond because she was always to busy to do anything with me. I felt kinda left out because everyone else had such a great bond with their bigs that when it came time for my initiation I didn't feel the same. Afterwards the girls all exchanged gifts and most of my pledge sisters got lavaliers from their bigs. I remember wanting one so badly and was kinda disapointed not to get one.
At any rate you're not the first this has happened to. It's unfortunate but like everyone else said, simply write your big an email and explain to him how much you wish he could be there. Don't guilt trip him though.
I can't believe one of your brothers would say for you to buy your own letters
I think that's just rude...
Anyways, good luck and try to just enjoy the initiation for what it is. They're ALL your brothers so that's the important thing.
Hootie