Is there any drop -in alternate parts available for K78L05-500R3 other than MP-K78L05-500R3
If you don’t need a module that can also do -5V output, the following Murata Power Solutions part may work for you:
7805SR-C Murata Power Solutions Inc. | Power Supplies - Board Mount | DigiKey
Kindly check the specifications to see if it may work for your application.
Here’s a link to a bunch of 7805 drop-in type DC-DC replacements, some of which are more affordable than others. You should check datasheets for any differences which might be relevant in your particular application.