User tabular data entry to build a budget worksheet? I am trying to build a budget worksheet where users can enter their budget information and save that until the next time they need to update it.  Each user will only have access to their budget sheet.

I spent approximately 16 hours on trying to get Sheetnode and PHPExcel to work, but that is really buggy in my humble opinion (may also be my lack of knowledge).

I'm not really looking for a "how-to" but rather someone point me in another direction where I could possibly find success.  I don't really know what keywords to search in google for what I need to do, but I keep stumbling upon webform, which is a nice module, but does not do what I need at all.
You could try https://drupal.org/project/tablefield or https://drupal.org/project/slickgrid
From module page:

The Slickgrid module is an implementation of Michael Leibman's jquery slickgrid plugin, a lightening fast JavaScript grid/spreadsheet.
It defines a slickgrid view style, so all data can be output as an editable grid.
This module will only work with Slickgrid 2.1.

These do not provide spreadsheet functionality, but you would probably implement the summation or whatever calculation is necessary.