I was again coming back from the sea and a question hit me like a ton of feathers. it is based on Kidushin page 8a the second Tosphot. From that Tosphot we can see that Tosphot holds the value of money is like money, not like exchange. the reason I say this is because Tosphot is discussing the sugia of Rav Josef who learns the value of money islike money from a Jewish slave. but right away Tosphot says a Jewish slave is not acquired nor acquires himself by exchange. he can be bought only with money or the value of money, not exchange. there the question of Rav Shach cannot begin. Rav Shach asks on Tosphot page 2a who says we learn the value of money is like money from a Jewish slave. Question: that is only half a gezera shava because he cannot be redeemed except by money. This might be a good question on the Rambam. But Tosphot holds a Jewish slave can be bought or sold by the value of money because the value of money has no connection with exchange. The whole question of Rav Shach is based on the fact that the Rambam holds the value of money is like exchange. This has no connection with Tosphot. To Tosphot, the value of money is like money, not exchange. Now there might be a question here on the Rambam if we would know from what verse the Rambam learns the value of money can acquire a woman. But so far, I have no hint of what the Rambam might say about that.--------------------------------------I was again coming back from the sea and a question hit me like a ton of feathers. It is based on קידושין דף ח' ע''א the second תוספות. From that תוספות we can see that תוספות holds שווה כסף is like money, not like exchange. the reason I say this is because תוספות is discussing the סוגיא of רב יוסף who learns שווה כסף is like money from a Jewish slave. but right away תוספות says a Jewish slave is not acquired nor acquires himself by exchange. he can be bought only with money or שווה כסף, not exchange. there the question of רב שך cannot begin. רב שך asks on תוספות דף ב' ע''א who says we learn שווה כסף is like money from a Jewish slave. Question: that is only half a גזרה שווה because he cannot be redeemed except by money. This might be a good question on the רמב’’ם. But תוספות holds a Jewish slave can be bought or sold by שווה כסף because שווה כסף has no connection with exchange. The whole question of רב שך is based on the fact that the רמב’’ם holds שווה כסף is like exchange. This has no connection with תוספות. To תוספות, שווה כסף is like money, not exchange. Now there might be a question here on the רמב’’ם if we would know from what verse the רמב’’ם learns שווה כסף can acquire a woman. But so far, I have no hint of what the רמב’’ם might say about that.