If I go to a users feedback and see 100 bond trades, or a user with a few 100M trades, it is up for me to decide who is more trust worthy. Number of feedback doesn't mean "trustworthy" to me. My one feedback is worth more than about 50% of people with over 100 that are doing bond trades. It is your judgement to go through and see what they are. If someone has a bond shop and has sold over 500 bonds they would have 0 feedback according to your logic. Just because they didn't do as much wealth doesn't mean they aren't trusted. It is all about how you look at it.
I think a bond is the perfect amount.