Responsa for Kiddushin 100:2
<big><strong>גמ׳</strong></big> וצריכא דאי אשמעינן שוה פרוטה איידי דקא נפיק ממונא מיניה טעי אבל פחות משוה פרוטה אימא יודע שאין קידושין תופסין בפחות משוה פרוטה וכי קא משדר סבלונות אדעתא דקידושין קא משדר
For if we were informed the case of a perutah's worth [for two women], [I might argue,] since money has gone forth from him, he may err [and think the kiddushin valid]. But [with respect to] less than a perutah's worth, I might say that he knows that kiddushin with less than a perutah's worth is invalid, and so when he sends gifts, he sends them as kiddushin.<span class="x" onmousemove="('comment',' And the fact that no declaration accompanies them makes no difference, such being unnecessary when preceded by marriage negotiations: v. supra 6a.');"><sup>3</sup></span> And if these two cases were taught, that is because one may not be clear on a perutah's worth and less;<span class="x" onmousemove="('comment',' He may have over-estimated the value of the article.');"><sup>4</sup></span>
Teshuvot Maharam
A. If there are witnesses that A proposed to Leah on a previous occasion and that she accepted his proposal, she is betrothed to A, even though A did not expressly say he was betrothing her. When there are no such witnesses, but both, A and Leah, admit that they had a previous understanding between them, or that at the time A gave the money to Leah they both intended the money to bind them in betrothal, Leah is betrothed to A. Moreover, the mere statement of A to Leah that he gave her the money as a token of love may constitute a betrothal, and therefore, Leah needs a divorce from A before she can marry another.
SOURCES: Cr. 19; Pr. 519–520; Mord. Kid. 521; Tesh. Maim. to Ishut, 4.