Astra sp and derby extra are the two best for the $$ IMO.
[emoji106]I've never tried a Bic Chrome Platinum blade. I'll put it on my future must try list.
Nacet & Personna Red's!
Depends on whether you mean now or over a period of time. Blades seem to vary in price depending on availability. I got 100 Astras delivered to me and 100 Voskhods - both for under $10 per hundred including the shipping. Those were great value blades.
How about both past and especially present.
I just purchased another 100 Nacet, for $14.21 delivered.
I am in the middle of testing a Nacet blade, and I really like them.