One possible drawback to playing any CV with a wagering system based on
putting a price on each piece is that it seems it would make the game more
materialistic. One of the endearing features of Chess is that its focus on
the Kings makes spectacular sacrifices for the sake of achieving checkmate
worthwhile. But if the point of the game is to end with the greatest value
of pieces still on the board, I think this aspect will be lost. A player
who hopes to win would play conservatively, trying to keep his own pieces
on the board rather than let their value fall into the hands of his
opponent, while a player who fears losing would try to make exchanges,
thereby reducing the value of the ultimate prize for the winner.

For whatever it's worth, I proposed a variant called 'Contract Jetan'
in a letter to a 2001 issue of Abstract Games magazine, which went about
like this: In Contract Jetan, a player could propose in mid-game some rule
change that would make it more difficult for his opponent to win,
accompanied by a 'proffer' of some tokens that would be added to the
ante if the opponent accepts the dare. Such a proposal would probably be
made by the player in a weaker position. For example, 'You must win in
the next 15 moves or forfeit,' or 'My Thoat can only be captured by your
Warrior', etc. If the opponent accepts the rule change, the proffer is
added to the ante and the rule change is in effect. If the opponent
refuses, then the player who offered it has the option of 'buying out the
contract' as follows: from the proffer he removes a number of tokens equal
to the excess of value of the other player's army over his own, plus his
own Chief's value, and gives that to his opponent; then he adds the rest
of the proffer to the ante, and rotates the board half a turn. Then they
play on, but having reversed their roles, and with the proposed rule
change in effect.

This variant is played in an unpublished work that ERB left unfinished,
'Corporate Lawyers of Mars.'