Looks like you need a total of 200 of these - 100 to craft the Albino Snail, and then another 100 to put with the Albino Snail as part of the snail roll cake. Gonna be here a long time, as most of these pickups are a single snail.
Each snail pickup gives you one of three possibilities:
• 1 snail
• 4 snails (roughly 10-15% chance)
• 1 Magick Albino Snail (tiny chance, probably less than 0.5% )
I got an Albino after collecting 47 regular snails, but my understanding is that this was extraordinarily lucky. If you never find an Albino while farming these, you need 200 regular snails for the Snail Roll Cake recipe (the cook can convert 100 of them into an Albino). If you do get an Albino, you only need 100 regulars.
Respawn times per location vary wildly, ranging all the way from a few minutes to 20+. This makes farming loops unreliable, and there generally aren't enough people in Rohendel to generate multiple channels anymore, so I highly recommend spreading your snail farming out over time if you're not in a major hurry to complete it. In my case, I ended up setting a Bifrost point and periodically used it to run this route:
If you want to grind it faster, you can repeatedly return to the southern triport and keep running that line of 5 pickup locations. Just keep in mind that most of them probably won't be there for several loops if you're trying to do this quickly.
If you're having issues with other people fighting over the same snails, consider focusing on the western part of the map (near my bifrost marker) that's much harder to reach and likely to have fewer people.
Aight, my stats now :
I finished under 20 min (nobody around)
I could all take them twice, and around 80-90% of the time one of them was 4 the other was 1
I got 2 albinos ones before I reach 100 (before I got 60 actually)
I did tp bottom, all the way to the middle, tp top, both of them, then the 3 at the left