If you want cheap but good PK type buds (11.88 usd), I finally found a recommended buds called "DIY PK2 SR2 PRO 16ohm".
"SR" seems to mean SunRise driver.
This has clear treble and deep bass, so really sounds like SWD2Plus! Please try this with donuts pad.
https://www.aliexpress.com/item//32801890526.html
Nice, looks like a cheap way to finally try PK shells! That graph makes them look pretty bass-y, have you tried them yourself next to the SWD2Plus?