Yes, they sell 3 pack [1]. I bought it about 3-4 years ago and back then they also sold 3 pack. I immediately stored it in the fridge together with my Li-On batteries. I used one about 6-12 months after, and it was still OK, but it was red (they had a special deal of 3 diff colors for cheap) and the surface was black, so, not very pretty. Now I bought 3 black around black November and I assume its still good. I don't often use it (or forget to use it) which is kinda meh. But you could argue the reason I don't use it is a lack of creativity. I mean, check the website. So many uses for Sugru!

[1] https://sugru.com/buy#3-packs