https://pso2.com/news/announcements/valentines2021
Scroll down. A lot of important stuff here. Such as: S7 Still Grace, S8 Skydance Support, S4 Steadfast Will, etc.
For possible prices, [click here] and scroll down to 限定ACリサイクルショップ (2020/09/23-2020/09/30)
What will you be buying? And how many badges did you end up investing in when they were cheap?