Providing your stropping technique is OK, using just one razor should get you up to 6 months I’d guess. He fact is that technique is all important - the old joke about straight razors is that the more you use them, the sharper they get. There’s another truism that the more you get into straights, the more razors you acquire - which of course helps extend the working life of any particular one.
Let me make you an offer - if you are still using straights in 3 months time, I’d bet you have more than one by then. If not, let me know and I’ll send you a decent quality razor as a gift.