Tosfot says that ripuy and shevet are included and absorbed into nezek, according to one way of learning. and that when we evaluate damage in the market place, there is no distinction between for example a sick three-legged ox and a healthy three-legged ox. Rabbeinu Tam disagrees with this limud and says that since we don't estimate tzar and boshes, and ripuy and sheves are only a little amount more, therefore the buyer and seller in the market place work out between them the sheves and ripuy and we don't make an official estimate. However on daf mem beis amud beis in Gittin, we see the in a case of "lo calya karna" we say according to Abayay that sheves is estimated separately from other damages. Furthermore, if we are saying that Tosfot, and Rabbeinu Tam says that by the ox you can sell it, therefore you don't get extra money, we see and Tosfot on daf yud that says you never have to sell the shor if you don't want to. let the nizuk say he doesn't want to sell the shor.
Noach Dreyfuss, Jerusalem, Israel
Tosfos says that Ripuy and Sheves are included in the evaluation of Nezek. This does not mean that there is no difference between a sick three legged animal and a healthy one. Obviously there is a difference in cost. See also Rabeinu Chananel in Tosfos Gitin 42b (DH v'Shor). What it means is that the damage of Sheves and Ripuy is covered by the Nezek.
I have not seen Rabeinu Tam on this subject, where is it brought in the Rishonim? I do not understand what you mean when you say that the buyer and seller in the market place work out the Sheves and Ripuy. There is not necessarily a buyer or seller if the Nizak does not want to sell.
Tosfos does not mean that the Nizak must sell the ox, just that the Nizak could sell the ox if he would want to and buy a healthy one and therefore we measure the Sheves and Ripuy as the difference in cost between the healthy animal and the ill one.
Dov Freedman