I used to shave once a week. I bought a safety razor ($20) and 100 razors ($20) in 2015 and only ran out about a month ago. I ordered 200 more razors ($40) and decided to start shaving every day. I find a razor is comfortable enough for about a week, so I expect to get about 3+ years out of them. I have a pretty heavy beard with thick black hairs, I'm not sure if that has an actual effect on how quickly a razor degrades but, if it does, I expect it could last that long for most. I use hand soap as "shaving cream", which I buy to wash my hands anyway. I prefer the auto-foaming kind but liquid and bar soaps work just as well.