It's hard for me to say exactly but honestly those are modest numbers I gave you up there, I'm bored enough so I'll give it a crack. I'll put (?) next to anything I'm not too sure
2 systems $20 each (not too sure on system value)
X-Men vs. Street Fighter (this game was Japan only) (?)
Albert Odyssey - $60
Hang-On GP - $1
Bug! - $1
Croc: Legend of the Gobbos - $1
Madden 97 - $0
Bomber Man - $30 (?) (this is my favorite bomberman of all time)
Daytona USA - $0
Shinobi Legions - $25
Road Rash - $1
Frank Thomas Big Hurt Baseball - $0
Worldwide Soccer - $0 (my favorite soccer game of all time)
Panzer Dragoon II Zwei - $30
NHL All-Star Hockey - $0
Cyber Speedway - $1
Madden 97 - $0
World Series Baseball - $0
The Mansion of Hidden Souls - $5
NFL Quarterback Club 97 - $0
Fighting Vipers - $1
Sonic 3D Blast - $1
Dragon Force - $70
Iron Storm - $15
Astal - $15
Street Fighter Alpha - $5
Street Fighter Alpha 2 - $5
Marvel Super Heroes - $20
Guardian Heroes - $60
Nights - $15
Dark Savior - $20 (this is a great game I love climax)
Mega Man 8 Anniversary Collector's Edition - $70 (?)
Bust-A-Move 2 Arcade Edition $5
Night Warriors - Darkstalkers' Revenge $10
Virtua Cop 2 + Blaster - $30 (?)
NHL 97 $0
Virtua Cop - $0
Virtua Fighter 2 - $0
These prices are CIB, if they aren't CIB then the $150 price seems right
According to my calculations it's worth about $537 so the most I would offer is $250. I would def try to just get it for $150 tho you will easily make $250+ profit. If you are going to sell it I would make 2 saturn system + games lot (split the commons evenly) then just sell the valuable game induvidually.
EDIT - to post below the reason to offer $250 max is that he had it listed for $150 so if you are easily willing to pay close to double then it's going to send a red flag that he is doing this the wrong way and he may not sell you it at all.