I don't know about others but when I first got into wet shaving specifically DE it was partially due to how damn expensive carts were getting per blade. I decided to do some comparisons to see if SE and injector blades stack up cost wise. My estimates are based upon how many shaves I can get out of a blade, pricing is in USD with shipping factored in for representative vendors. For DE blades I get 6 shaves on average same as an SE and for injectors 10 shaves on average. Which one is the most economical, well it will depend on upfront cost for starters. The larger the quantities the less price per shave would be expected so using my preferred blade which is a BIC Chrome Platinum that will be the basis of this. First up a 100 pack of Bic Chrome Platinum blades sold on amazon here this includes free shipping. https://www.amazon.com/dp/B00YH25IWM/?tag=thshde-20 6 shaves * 100 blades = 600 shaves per 100 pack Price of $14.99 / 600 shaves = approximately 2.5 cents per shave Now for 240 Personna ptfe coated stainless injector blades with the keys sold here by razorbladeco which include free shipping. https://www.razorbladeco.com/89-0043-coated-injector-blade-in-dispensers 10 shaves * 240 blades = 2400 shaves per 12 injector keys @20 blades per key Price of $52.00 / 2400 shaves = approximately 2.2 cents per shave Finally Gem ptfe coated stainless SE blades sold in 100 and 200 pack quantities by Connaught, price includes shipping to USA. https://connaughtshaving.com/gemss.html 6 shaves * 100 blades = 600 shaves per 100 pack Price of $18.24 / 600 shaves = approximately 3 cents per shave 6 shaves * 200 blades = 1200 shaves per 200 pack Price of $31.32 / 1200 shaves = approximately 2.6 cents per shave End result is if you want to buy in big enough quantities it is pretty much a wash on the cost per shave per blade for either of the 3 platforms using these blades here. Upfront costs DE will be the cheapest and should be the overall cheapest option if you go for blades in 100 packs that are cheaper than Bic blades like Voshkod blades for example which can be had for $6.98 for a 100 pack on amazon with free shipping. DE is still the cheapest option upfront and price per cost per shave when the 100 packs of blades are approximately $14 or less.
To put one other thing in perspective assuming no leap years you would have enough blades to shave daily for x amount of years when you purchase in these quantities. DE/SE 100 blades @ (600 shaves / 365 days) = approximately 1.64 years DE/SE 200 blades @ (1200 shaves / 365 days) = approximately 3.28 years Injector 240 blades @ (2400 shaves / 365 days) = approximately 6.5 years
One other blade to compare. If someone can find a better price let me know is the Chinese Schick injector blades since these are a commonly used blade by injector shavers. For amazon here is a vendor selling 12 packs of them with free shipping. https://www.amazon.com/dp/B018J7L3IS/?tag=thshde-20 10 shaves * 84 blades = 840 shaves per 12 injector keys @7 blades per key Price of $58.92 / 840 shaves = approximately 7 cents per shave Personna blades not surprisingly are the better value dollar wise over the longer term when you rate them strictly by cost per shave.
Might as well do the Schick Proline B-20 injector blades also to see how they stack up. I'll use Connaught again as the representative vendor. They sell them in 20 blades per key up to 100 blades or 5 keys. Price includes shipping to the USA. https://connaughtshaving.com/spb20.html 10 shaves * 100 blades = 1000 shaves per 5 injector keys @20 blades per key Price of $50.74 / 1000 shaves = approximately 5 cents per shave One other point to add though is that Connaught has a flat pricing so the upfront cost to get 5 cents per shave is the same whether you buy a single key @ 20 blades or multiple keys.
Using this vendor here on Rakuten, blades listed as chic babies B-20. They offer free shipping on the blades for international supposedly. https://global.rakuten.com/en/store/ha-life/item/twoinone0549/ I'll price it by 12 injector keys same as the Personna blades to be consistent. For Schick Proline B-20 blades 10 shaves * 240 blades = 2400 shaves per 12 injector keys @20 blades per key Price of $84.36 / 2400 shaves = approximately 3.5 cents per shave They are more closely priced than I expected anyways. They only carry a more upfront cost only if you buy the same amount as the Personna blades listed above. If you buy then in the same quantity as at Connaught for 5 keys @ 100 blades that is $35.15 shipped or approximately 3.5 cents per shave also. If you buy any smaller quantities the cost per shave jumps on the pricing with this vendor.
