Responsa for Bava Kamma 229:26
מתקיף לה רבא השתא לוקח מגנב עשו בו תקנת השוק לוקח מלוקח מיבעיא
whereas regarding the latter four <i>zuz</i> you can demand your money and [then] return the garment. R. Cohen demurred: Why not say that the garment was delivered in consideration of the first four <i>zuz</i> [exclusively], so that it would thus be a case of misappropriating articles and paying [with them] a debt, or misappropriating articles and paying [with them] for goods [received] on credit, whereas the further advance of the last four <i>zuz</i> was a matter of mere trust,<span class="x" onmousemove="('comment',' And if so, the plaintiff should be entitled to recover the garment without any payment whatsoever. ');"><sup>45</sup></span> just as he trusted him at the very outset? After being referred from one authority to another, the matter reached the notice of R. Abbahu who said that the law was in accordance with R. Cohen.
Teshuvot Maharam
A. A owes that amount to B. Since the court has a right to distrain a debtor's article for the benefit of the creditor, the court may surely confirm B in the possession of the book after the latter pays to A the difference between its actual value and the price he had originally paid. If B paid C for the book more than the latter paid to the Gentile, C must return the difference to A.
SOURCES: Am II. 138.