You are pretty new here . You would have to search a lot to find anyone needing to actually buy some blades. Most could shave a few lifetimes with their stock.Besides, how long does it take to run to the pharmacy to get a new pack of cartridges because you swear you put them on the shopping list for the grocery store? How long does it take to order packs of blades online, enter shipping, billing, credit card info, and then wait for it to arrive?
When you order blades online you most of the time buy at least 100 blades, so the time it takes for entering payment info is actually very low comparing to the amount of blades. Before I have used all 100 blades you have spent much more time on maintaining your edge.
For me DE is the most convenient way of shaving. The maintenance is minimum, blades are cheap and they do not clog easily. Also I find the handle to be more comfortable than holding a straight. The result is pretty much the same regardless of what I use, so I see no reason to use a straight.