How can I make this table in our sales proposals clearer?

The company I work for sends out sales proposals to potential customers.

It is common for companies here to outsource Activity. If they do Activity in-house, they can save a lot of money. To do Activity in-house, they need to invest some money for training and equipment purchase.

We attempt to show this in a table in our sales proposals, but it is hard to follow and customers find it confusing.

Proposals are created in Google Docs, and a picture of the current table is shown below. This is intended to clearly show:

  1. The current cost
  2. The upfront investment required (and the components of this)
  3. The ongoing costs (and components of this)
  4. The resulting savings
  5. The ROI (return on investment) that this is equivalent to

Image of current table showing ROI.

This is confusing though! Customers find it hard to see where and how the savings are calculated, and there is a consensus that there is 'too much' (numbers, words) despite customers still wanting detail.

How can we rework this to make it clearer, easier to follow and more understandable — using only the design tools available in Google Docs tables?

(In saying that — we don't need to use a table, we can easily represent the information in text-only format instead if that is clearer).

Note: this is my first question in this site. I would appreciate any feedback about how to make it more specific/answerable, to fit the conventions of this site. Thanks for your consideration!