1031 exchange costs and interest payments from QI?

[Susan O.]

Hey I heard that some 1031 exchange QI's will actually give interest payment on the amount they hold?  Is that true?

For example--

$100,000 in a 1031 held for 3 months would cost the investor $500.  If the QI would pay 1% intersest on the $100k for the 3 months.  So the investor would gain $250. 

So the investor would only pay the QI $250?

Also if the 180 days expired is it typical for the investor to pay the QI less fees?

What are typical QI costs?

(this is just an example not real numbers)