Lang Syne features a single EX stage found under the Spring Prelude menu with the sole purpose of farming Red Packets, the event currency. The stage will always drop 200 Donations upon completion, split up into different quantities which can be purchased with keys.
This event shop becomes less efficient every time Keys are bought to continue farming currency, therefore it’s not advised. The shop is at its most valuable when only keys gained through natural regen or daily rewards (100) are used to farm currency.
Note: Claiming all 200 Red Packets provides a 10% discount which will be lost if any quantity is de-selected. Therefore it’s most efficient to always spend the 54 keys to receive all 200.
100 Red Packet = 30 Keys
50 Red Packet = 15 Keys
30 Red Packet = 9 Keys
20 Red Packet = 6 Keys
200 Red Packet = 60 Keys (Discounted by 10%) = 54 Keys
Let’s take a look at each shop and see what has reasonable value.
The price for the first 15 fragments is 50 Red Packets/Fragment or 15 keys each and 100 Red Packets/Fragment or 30 Keys each for the next set of 15.
The cost of daily Fragment Search is 5 Keys per stage, making both these options extremely inefficient even with the 10% discount applied.
If you’re capable of being patient, skip Daiyan’s fragments in the shop because they're simply not cost-efficient. However, if Professors are willing to sacrifice some Algo farming runs, these can be bought to save time developing Daiyan and is generally recommended.
This should be a given, but the Gacha Tickets are a clear must-buy.
Key refillers should be aware, however, that a ticket is worth 150 Quartz Sand, therefore if Sand is being used to farm currency, the value of your efforts declines the more Sand is spent.
In total these three tickets are worth 450 Quartz Sand. If this amount is exceeded while refilling keys to farm currency, you’ve basically wasted Sand.
These are a very subjective item because the value of them is determined by the Doll whom you plan to use them for Fragments. Regardless, they aren’t worth the cost in Keys at all.
The overall cost of all 150 will be 810 Keys, quite costly for only 25 Dolls Fragments at even the cheapest Neural Kit cost tier.
If Professor’s instead opt for getting those Doll Fragments via Fragment Search, they’ll only be spending 125 Keys for the same amount (and actually because of Fragment Search’s RNG, the actual amount gained will be closer to 30 Fragments).
Basic Search should give a steady enough supply of Neural Kits to not need to buy these. Basically Neural Kits are a scam, don’t touch them.
These boxes are available in very small quantities (2 per tier).
The value in these boxes come in the form of being able to select a specific set piece to obtain, but the main stat will be random, unfortunately. As a result, the value of these boxes depends on each Professor individually.
The 100 Red Packet boxes are absolutely worth it, costing the same per box as a single run of the highest Algorithm stage available (30 Keys). The 200 and 300 boxes will be left up to individual choice. They are inefficient as far as key spending goes, but the chance to get missing set piece may be worth it to some.
This is precarious item because the Factory recipe needed to craft it requires at least 15 orange Algorithms to be decomposed. The cost to get that many (assuming 2 orange drops per run) is about 240 Keys. However, that's just the hard cost.
The important fact about stat rerolling is that duplicate Algorithms can be used, bringing the potential cost for a reroll down to 30 Keys (provided you get dupes for the set you're rerolling).
Technically the Reconfiguration Generators are very cost-efficient when weighed against the raw cost of crafting them, so this item will be left up to player discretion.
X3 - 54 Keys each - 162 Keys Total
X6 - 84 Keys Each - 504 Keys Total
Note the total cost for the X6 set will be lower than stated if the 10% bonus is applied.
Get them if you want. They’re exclusive and unobtainable unless this event reruns.Aka the actual good shop.
These little devils cost around 18 Keys each and there are 45 available. They guarantee 1 completely random set piece. Unlike the boxes above, the set cannot be chosen. Still, the rate of Algorithm drops is usually between 1-2 orange per run (30 Keys), making this a fairly efficient shop item.
Buy it, then pray to RNGesus for something good.
A single run of the highest EXP stage costs 30 Keys for the same value as this shop item (typically between 8900-9100 EXP). At 15 Keys per 9000 EXP, this is a high-value item and the equivalent of the 2x Bonus seen on the daily farming stage.
Buy it and stock up.
The usual cost for around 4 of these is 30 Keys. The shop cost is roughly 10 Keys for 3. Very good value once more.
Buy it and stock up.
The total amount of tokens available to buy is 500. Since these cannot be farmed normally, their value is determined by each individual’s desire for furniture.
This item is valued at around 800(+/-) per 30 Keys. The shop cost is around 22-23 Keys per 1200. Easily a must-buy for a cheaper stack of 12,000 Skill Samples.
At base value these carry the same Key cost as their stage cost (10 Keys per). Considering the 10% Discount of taking all Donations at the end of its farming stage, it’s slightly cheaper than the stage cost too.
Plus, 12 guaranteed Pivots is a sanity saving value compared to spending the time required to farm 12 of them. Definitely a must buy.
Same value mark up as EXP.
Buy it and stock up.
This “infinite” shop is just to get rid of excess currency if any remains.
Do not farm specifically to buy anything here.
The challenge stage of Lang Syne is a bit different than Kuro's event. This time there is also a challenge mode with 3 different challenges available which each rewards 1x 30 Key Card for a total of 3. Don't forget to do it! The first challenge is always enabled, but the other two can be enabled one at a time if Professors are finding it too difficulty to complete all 3 at the same time.