Fish, coral and all I couldn't begin to think about what I have invested. In my 110 I have several ORA and Tyree corals that cost some big bucks (Not including my PPE's)

. I know just for my tank & equip, minus livestock, I have about $2k. I'm sure fish, rock, and coral I have at least that much invested. So consevratively I'll say $4k for my 110. And let me add I built the cabnet and DIYed everything I could to save money.
My 2.5 pico around $200 stocked.
20g frag tank, roughly $1k.
Wow, I could have baught a nice used boat for all that, LOL.