Helix 5,7, and 9 come with the compact transducer and it's recommended to upgrade to the HDSI transducer for better images. It is also recommended to exchange to a TM puck style transducer if you mount it on the TM because it has more shielding to reduce interference.
BTW those are nice images you have.
It's not $80 to exchange the TM ducer, I must've miss spoke. It's and even swap plus shipping.