If any of you are still looking, I saw this link from slickdeals. No idea about the seller though, but it is eligible for prime so maybe delivered before the game. No Shepard, but they have other ones.
https://slickdeals.net/f/11161991-latex-animal-head-mask-4-99-ac-fs-prime The original price is $9.99. Price after discount is $4.99.
Use Discount Code: KG2E5ACQ