First, I want to say, you might be able to get these at Dollar General, just depends on the cashier. Some say that they aren't allowed to use a coupon when the item will be free. I really don't think that is what is in their policy - so, it's easier just to price-match to Walmart.
Dollar General has several products Bic products for $1 this week.

Since this is in their print ad, you can price-match to Walmart.
Use the $1 off any one Bic Stationary product from today's newspaper coupon inert and get it for free! (limit of 4 coupons per household per day)

Also, I didn't find these in the regular aisle, they were in some bins with back to school supplies.