I've bought them at Canadian tire was well, but didn't mention it for the specific reason that they are so darned EXPENSIVE! $1 for a 8mm x 20mm bolt.. thats worse than highway robbery. I bought a box of 100 for $12 or so from Acklands. I certainly didn't use them all, but now I have stock bolts for the next time I need them and they ain't hard to keep. A box of 100 is 2" x 2" x 4"
FWIW
Jerry [Good luck on the project!
I'll watch for your project log to see what your building..]