Hope you don’t mind me saying this through here, and you don’t have to post this publicly but I used to be insane about doujins and I really recommend going through Dejapan. It’s been a while since I ordered from them so unless something changed they only really charge 100 yen per item (less than $1) and their shipping prices to US aren’t too bad as far as Japan shipments go, but ofc be prepared for a potentially high cost. I also used to order around 3 to 8 very nsfw BL doujins in one shipment (Japan to US) and never had any issues or opened packages as far as I’m aware.
Hope this helps and you can see it in time ^^; Their support team is also very fast to respond to emails if you have questions, and there are some reviews for the company online