Everything but the mask I already had lying around, accumulated around Toronto thrift stores and various other places. What I can remember:
Top Hat— Courage My Love, $75 (high school graduation present to myself)
Goggles— Army Surplus, $40
Beaked Mask— Malabar, $15
Cane— somewhere in Chinatown, $3
Tailcoat— Black Market, $10 (what a find!)
Black w/ Red Pinstripe Waistcoat— H&M, $15
Tie— Exile, $3
Black w/ White Pinstripe Dress shirt— Hot Topic, $10
Turtleneck— H&M, $15 (all about the layering)
Skinny Grey Jeans— H&M, $30 (not "period" by any means, but I wanted to look really distorted—hence, big hat, wide shoulders, skinny legs. plus, the grey is nice.)
Shoes— Moores, $40
Of course there was no need for Plague Doctors in the real Victorian era, but those engineered viruses can be so awfully persistent...
Many thanks to sight for putting this into my head in the first place.
Now comes the hard part: resisting the temptation to dress like this every day.