my home depot and lowes are no longer carrying individual blocks. Called a glass block company - guy thought I was strange but said he would sell the 8X8 for $2.90 each. Thought I was crazy to try to put a hole in them.
Danaoh, what dept. were you in? Our Lowe's has them in the flooring area over by where the carpets are hanging. Maybe the guy you talked to just didn't KNOW. LOL Can't imagine that they wouldn't carry them anymore, lots of people use them in bathrooms.
I was hoping they had the plastic ones--I wanted to see what they look like because they would be so much lighter weight. My Lowe's didn't have any plastic ones.
Good luck with doing your drilling--I am still sort of chicken to try it.