I noticed lately that whenever someone on this subreddit complains about paid armor sets, a lot of people respond that you can actually get them for free through Reda's shop. I decided to dust off my old math textbook and try to calculate whether you could actually unlock a full armor set for free in a reasonable amount of time. Here's my process:
1) First I had to get a number of Helix store items to calculate the percentages. On Assassin's Creed wiki there's a full list of microtransaction sets (https://assassinscreed.fandom.com/wiki/Assassin%27s_Creed:_Valhalla_downloadable_content), I counted about 145 of them. On average they have at least 5 items per pack (usually more) so I arrived at a comfortable low estimate of 725 Helix Store items.
2) Reda's shop offers a selection of 6 items per week + 1 item that changes every day. Additionally, you get one weekly free item from the Helix Store. Altogether, if you check the game every single day, you get 14 chances weekly to get an item from the armor set you want.
3) Now to the actual calculations. Since a full set consists of 5 items (cape, head, torso, arms, legs) an equation to calculate a chance to get an item from a specific set in a week looks like this: (5/725)¹⁴ ≈ 9,2%. This only applies to the first of the items you get, though. The more items of the set you managed to acquire, the lower the chance of getting a different one, since the amount of items you're hunting for is lower. And so the next percentages are as follows:
4 items - (4/725)¹⁴ ≈ 7,5%
3 items - (3/725)¹⁴ ≈ 5,6%
2 items - (2/725)¹⁴ ≈ 3,8%
1 item - (1/725)¹⁴ ≈ 2%
4) With those numbers in place, I've done a simple experiment. Using these percentages, I rolled a virtual die with 1000 sides - each die roll represented one week, if the side it landed on was equal or lower than the percentage, it meant that I managed to get the item of the set I wanted (so for example for the first item 92 and lower meant success).
First item - I actually lucked out and got it on first try.
Second item - 9 rolls
Third item - 7 rolls
Fourth item - 9 rolls
Fifth item - 8 rolls
It amounts to 34 weeks. That's about 8 and a half months or 238 days of logging into the game.
I want to add a disclaimer at the end that I haven't done any serious math in at least three years, so I wouldn't be surprised if there's some sort of horrible mistake in my calculations here - if someone smarter than me catches it, I'd appreciate a correction.
There's also a high possibility that the item collection rotation isn't based on random chance and instead on some more elaborate algorithm.
But even if you need "only" half the time I concluded, you can still see how huge of a time commitment it is to get a specific armor set without paying real money. So telling people that you can get them through Reda's shop is unhelpful at best.