Help with working out loan cost

Hi everyone, im new here, and new to investing in property.

I was looking at some investment calculators on the net and they seem to have a lot of assumptions. One of them is ‘loan costs’ to set buy a property.
One figure I saw for a $250k property was $3000 in loan cost. I thought the usual cost was about $600? What gives?

Also depreciation. It was $3000. Is there a common schedule, or percentage used? Or is this figure particular to each property?

I want to make sure I have some accurate figures so I can look at some investment options with a little more clarity!

Thanks in advance