Look, Stardew Valley might be a genre-defining, culture-shaping phenomenon, but if you're on your Nth playthrough like me, you might be looking to switch up the vibe. You can definitely make some wacky choices in this game, like funding the evil Joja Mart or choosing violence against Linus, but what about when it comes to romance? Well, if you're looking to go full sadist and break the hearts (and probably spirits) of all twelve bachelor(ette)s in Stardew, I've been crunching the numbers on how much in-game time and gold it'll set you back.
The math is relatively simple: you need 250 points for a heart, and to get a villager to marry you, you need ten hearts. This means you need 2.5k points. Every week (assume I'm talking about in-game time from now on), you can talk to a villager once a day, which gains you 20 points towards your heart total. Multiply this by each day, and you get 140. This is on top of a maximum two gifts per week, which, if you find the loved gifts, can net you 80 points per gift, so 160 per week. That means as a baseline, with chats and gifts combined, you should be able to get 300 points per week.
2.5k divided by the 300 points you can get in a week is just over eight weeks, but we'll round it down because of the points you get from other sources, especially heart events, which can give you anywhere between ten and 80 points. The final step is finding a rainy day, or, if in winter, creating one with a Rain Totem, which we recommend preparing in advance if you can find the time in between wooing your future ex-spouse.
After that, it's a three-day wait, and you're married. You can get divorced the very next day. In theory, then, the cycle can repeat roughly every eight weeks. There are currently twelve marriage candidates, so eight weeks times twelve people is 96 weeks, or, by Stardew's clock, six years. This also doesn't account for the fact that you can be working on gaining the favour of multiple candidates at once, which would cut the process down significantly - but just be careful you don't hand everyone a bouquet at the same time, or your progress will be wiped due to jealous lovers.
Having said all this, it's hard to make these calculations exact. Stardew Valley has a number of variable systems that make it hard to predict exactly how many hearts you can gain with someone each week - these include special requests on the board, getting caught rifling through the bins, and choices during heart events. These calculations also assume that you can find loved gifts, which is why I recommend an order for the speedrun.
The easiest candidates to acquire loved gifts for are Shane, Leah, and Abigail, so unless you want to end up with one of these three, we recommend starting with them so that you can start giving gifts right away. Stardew Valley's Shane loves pizza and beer, and Stardew Valley's Leah is into salad, which are all easily bought in the Saloon, while Stardew Valley's Abigail loves amethyst, which is one of the easiest gems to get in the mines.
You'll have to have the coin for both the gifts and other expenses that will crop up. Don't worry, I've done the math here, too. In total, for dating, marriage, and divorce costs alone, you'll need 662k gold, as each bouquet is 200 gold, a pendant is 5k, and each divorce is a whopping 50k gold. If you want to scorn everyone but an eventual endgame spouse that you stay married to, you can take 50k off that amount, naturally.
If you're up for the challenge, you can truly make life a living hell in the valley, though this divorce speedrun will naturally take up a lot of your time. This is in part because you'll have to find the villagers and their gifts, as well as progress some of the game's systems enough to be rich enough to afford the process. Plus, you'll need to be able to craft Rain Totems, which you can only do by getting to Foraging level nine.
Of course, given the announcement of the Stardew Valley 1.7 update, two new marriage candidates will be entering the fold. It will give me great pleasure to divorce Stardew Valley's Clint, but to divorce him and Stardew Valley's Sandy will add another year approximately, and, given where Sandy is located, you'll have to tackle her wooing and subsequent dumping a little bit later on in the run. So, fairly soon, this whole process will be an extra year longer and an extra 100k more expensive.