It's not that they were expensive (the HDD + adapter probably being the most expensive part), but rather that the PS2s on the used market are so cheap no one was willing to pay the extra, even if it's been refurbished.

He said in the comments on the post that he valued the parts, units, and his time at about 100 bucks, and put them up for 150, which no one would pay. This was back in 2022ish.

that's less than i was expecting. i was looking for a ps2 around then and i'd definitely have paid $150 plus shipping for all of that.