replacing cracked glass screen on imac 27

What year is the iMac? 2011 and earlier models it's very simple. 2012 and later it's best to have an AASP do the work as the glass and display are bonded together meaning that they are one unit and must be replaced together.

I will not touch on costs as I don't know what the problem is really because you didn't answer my question and costs vary by region.

Because we don't know the extent of the damage or how it was caused it's impossible to say if it would affect internal components of the computer.

You are looking for answers, however you need to take the computer to an Apple Store or AASP and they can answer all of your questions after inspecting it. A forum cannot really help with a damaged computer.

We have no idea know where you are and can not quote on behalf of a service technician.

It is a simple matter of googling/or phoning around and getting a real quote, not a quote from us who will not be doing it.

Peter