Take notes, and enter into a Google Docs spreadsheet using Google Assistant.
Ok,this is actually pretty simple on IFTTT - it's lucky that it's a simple task. 

Here's an applet I created: 

https://ifttt.com/applets/91022983d-if-you-say-spent-on-then-add-row-to-google-drive-spreadsheet

Essentially you can create a text and number trigger for google assistant, that maps nicely to creating rows on a spreadsheet.