Vintage Gillette razor blades have a very loyal following under the shaving fraternity, and no serious collector would give up an opportunity to get his hands on some of these. Apart from the collectors there are some users that love the blades so much, they buy them up whenever they can to use for their daily shaves, needless to say this will constantly erode away at the availability of these, so use sparingly if you can!
The super blue blades are coated carbon steel blades, so more than likely not as smooth as the stainless steel blades, but they could be very sharp when kept in a good state. Collectibility is what drives the price up on these okes, if you have (or are planning to collect some pristine old razors) you simply must have a pristine set of blades than came with the set and is era-correct. These boxes are 'new old stock' the plastic wrapping aroun them are pretty tatty, but the boxes are unopened, so the dispensers will still be in brand new condition.
Enjoy on special occasions using that special razor or keep for display purposes only.