Betrothal with money has to be with something that has a clearly defined value. With a parallel to pidyon haben - redemption which also needs to be of a certain value. Also, what happens if the woman takes the money a man offers her for kiddushin and she destroys the money? Is that rejection of kiddushin, or is it too late? Or does she owe him the funds?

[NOTE: If the second part of today's daf sounds familiar from yesterday's daf, you are not wrong. It was a good we will share (maybe) at the siyum for Kiddushin. In the meantime, check Daf 7 soon for a renewed second half.]