
Originally Posted by
Xitra
Let's start with a 4x boost for 6 hours. As you say, it knocks off 18 hours of builder time. Let's give it a cost of 150 gems, per your suggestion.
Three scenarios:
1. I start a 1 day build/upgrade. Total cost to gem completion? 260 gems.
1a. I wait 6 hours. With 18 hours left, the cost to gem completion is 197 gems.
1b. I spend 150 gems to boost my builder, and 6 hours later, the building is complete.
2. I start a 2 day upgrade. Total cost to gem completion is 383 gems.
2a. I wait 6 hours. With 1 day 18 hours left, the cost to gem completion is 352 gems.
2b. I spend 150 gems. 6 hours later, there is 1 day left to complete the build, for a cost of 260 gems. Total cost if 410 gems.
3. I start a 7 day upgrade. Total cost to gem completion is 1000 gems.
3a. I wait 6 hours. With 6 days 18 hours left, the cost to gem completion is 969 gems.
3b. I spend 150 gems. 6 hours later, the are 6 days left to complete the build, for a cost of 876 gems. Total cost, 1,026 gems.
In scenario 1, you save a few gems (47, assuming the gem costs are accurate). However, as scenarios 2 and 3 point out, boosting the builder actually increases your total cost in gems (by about 57-58 gems). This is why it matters that it's not linear.
Based on what I could find online, the cost per day of builder time is about 123 gems per day, for anything longer than a day. I'm not sure how accurate that is, but it's in the right ballpark for the shorter builds I've seen (less than 10 days). Indeed, it works out to 11 minutes 40 seconds per gem, which is what I'm observing on a 2-day build as it counts down.
Thus, shaving 18 hours off a build would save you about 92 gems. Using dahimi's 75% guideline, boosting a builder should cost about 70 gems for 6 hours, to give a nice round number.
Personally, the benefit seems too little to be worth a whole lot, at 70 gems per 6 hours of 4x boost.
For an 8-day build, it would cost 1,123 gems to finish the build instantly. You could wait 2 days, then gem it complete for a cost of 877 gems. So you spend 78% of the gems to finish the building in 25% of the original time, which is fair-ish. Save 22% of the gems, at the expense of 25% of the time.
Or, you could boost 8 times to finish the building in the same 2 days. At 70 gems per boost, you'd be spending 560 gems, or essentially half the original cost to gem completion. So you'd save 50% of the gems, at a cost of 25% of the time.
I think something closer to 40-60 gems might be more reasonable. Warren suggested 40, right?