By clue 6, the players sold their games for differing amounts from $1030.
Neither Outlaw Planet (clue 2), Roller Ball (4), nor Mall Tycoon (5) sold
for the high of $30, so either Age of Kings or Volcano did. If Volcano had
sold for $30, Outlaw Planet would have gone for $25 (2). By clue 1,
Age of Kings didn't sell for the low of $10, since the player who sold it
got $15 more for it than he paid for the game he bought. Therefore, either
Roller Ball in clue 4 or Mall Tycoon in clue 5 went for $10. In either case,
by clues 4 and 5, the fourth price would have to be $20. Age of Kings had
to sell for at least $25 (1, 6). So, the one of Roller Ball and Mall Tycoon
that didn't sell for $10 would have brought the $20. However, by clues 4 and
5, a game would have cost $40no (6). So, Volcano didn't bring its owner
the high of $30; Age of Kings did. By clue 1, then, a third price must be
$15. If Outlaw Planet in clue 2 had gone for the low of $10 and Volcano then
for $15, since no two games brought the same price (6), Roller Ball and Mall Tycoon
would have sold for two prices not yet determined. However, by clues 4 and 5,
there would then have to be sixth and seventh pricesimpossible. So, either
Roller Ball or Mall Tycoon brought the low of $10; and we have a fourth price
of $20. If Outlaw Planet in clue 2 had sold for $15, with Volcano then having
gone for $20, the one of Roller Ball and Mall Tycoon in clues 4 and 5 that
didn't sell for $10 would bring a fifth price different from the four already
established (6). Again, however, from clues 4 and 5, there would be an
extra price. So, either Roller Ball or Mall Tycoon sold for $15by clues
1 and 4, Mall Tycoon did. Roller Ball brought $10. Chris sold Age of Kings
(5) and bought Mall Tycoon (1). By clues 2 and 6, Outlaw Planet must have
sold for the $20 with Volcano going for $25. Alex bought Outlaw Planet (4).
By clue 1, Eric bought Roller Ball and netted $10 after selling Outlaw Planet.
By clue 3, Brad bought Volcano and sold Mall Tycoon. By elimination, Daniel
ended up with Age of Kings. From the introduction, each player bought a
game from a different player than the one to whom he sold a game. Since
Alex bought Outlaw Planet from Eric, Alex couldn't have sold Roller Ball to
Eric. Daniel sold Roller Ball. Alex sold Volcano. In sum, the video games
were dealt as follows:
 Chris sold Age of Kings to Daniel for $30
 Alex sold Volcano to Brad for $25
 Eric sold Outlaw Planet to Alex for $20
 Brad sold Mall Tycoon to Chris for $15
 Daniel sold Roller Ball to Eric for $10


