My budget is 60k$. Im comparing some SHA-256 devices (10x Antminer S19 Pro seems like a good fit at the moment) and by my very rough estimates, based on current prices, I should be breaking even within 18 - 24 months. Electricity cost from where I'm based is around 0.03$ - 0.06$ kWh.
All these future predictions are of course nothing but "predictions", not something you can take to the bank, your break-even duration will depend on so many factors, some are unseen but let's just stick with the one that we are almost sure about.
1- The difficulty will only go up long term.
2- The price "unlike difficulty" can go up/down or either way.
3- It's a bit hard to maintain 24/7 mining operations.
4- It's very common for all mining gears to lose a hash board, a PSU, or die completely.
So in a perfect world, the math you do today should be applicable in the future, but since we don't live in a perfect world and given the 4 points above ( there are actually a lot more that serve the same purpose) you should ALWAYS consider the fact that it's very likely for these number to extend, the 24 months mark can be 34 months easily, ya of course if bitcoin goes to 1M right after you start hashing and China gets a blackout for 2 months you will break even in a month or two, but how likely is that?
I honestly believe that buying these mining gears at current prices is a bad business plan, even if works out for some people, it is nothing but a bad plan, 2 months ago many folks paid 14k for S19 pro when it was netting about $40 a day, they did the simple math that everyone does and they get 10-12 months, oh great, I am going all in, a short while after that the profitability for that mine fill form $40 a day to a bit less than 20$, it's now $24 based on 6 cents per Khw, the 10-12 months mark is now easily 16-20 months.
Of course, we don't know if bitcoin will climb back to 60k by next week or if it will take a year or two to get back up or even go back to 10k, but those folks will need a lot of luck to break even, and that does not take into account the fact that there is abosutlty no guarantee that any of those gears will work without a problem for 12 months or 24 months.
You might skip buying miners now and do the math a year later and regret it, of course, that is a possibility, but I would rather bet against it.