25 Undone Seal cards with current prices, from most to least expensive; the most valuable raw card is Regirock ex 055/083 ($603.06).
Regirock ex 055/083$603.06
Ninetales ex 018/083$450.79
Heracross 009/083$50.09
Kyogre ex 039/083$40.19
Milotic 025/083$40.18
Wigglytuff ex 058/083$40.07
Ninetales 017/083$30.16
Claydol 045/083$20.03
Pinsir 006/083$15.08
Crobat 007/083$15.02
Walrein 032/083$14.82
Medicham 054/083$10.06
Relicanth 036/083$8.01
Huntail 034/083$6.01
Rain Castform 026/083$5.01
Electrode 041/083$5.00
Gorebyss 035/083$5.00
Tropius 015/083$4.01
Whismur 062/083$3.52
Lanturn 043/083$3.00
Masquerain 012/083$3.00
Ancient Tomb 079/083$2.45
Nuzleaf 067/083$2.13
Surskit 011/083$2.00
Feebas 024/083$0.51