I was just looking at OPskins for the first time, and their suggested prices seem to be pulled out of thin air.
Ex.
https://opskins.com/?loc=shop_view_item&item=32340019
Smoking brigade suggested price $118.36 (the link and logo would seem to indicate that the price comes from this site)
http://backpack.tf/stats/Unusual/Brigade%20Helm/Tradable/Craftable/35- $25.82
https://opskins.com/?loc=shop_view_item&item=26571582
Abduction Phononaut suggested price: $1022.19
http://backpack.tf/stats/Unusual/Phononaut/Tradable/Craftable/91- $126.97
It seem almost like a borderline scam to me that the website would literally have "backpack.tf suggested price" and then a price that's 5-9x the actual backpack.tf price