Move your pricing block (H-K) before your competitor's (E-F), and remove either H or C (as they're the same).
Change J to Installation Cost (Before Tax)
Change K to Total (With tax)
Then change calculations accordingly.
If you need to have a value for taxes (like a competitor only tells you the price of an item after tax, but not before) then have a cell with JUST the tax modifier (10%-11%, or whatever it is), for both part and installation (or a single value if the tax rate is the same for both) . The tax modifier probably isn't going to change per part number, so set it off to the side of your table and refer to it as needed. If you want to drag and copy formulas and still use a single cell for calculations, use an Absolute reference (which is a reference using dollar signs, you can look it up if you're not familiar. Not too complicated).
Change L and M to "Is mine lower than my competitor's?", and only use a single field that's either TRUE or FALSE. Do the same with N and O. True/Falses are better to use, as they work easily with If statements. For example, using a single True/False field, you can do something like this:
=IF(3F, do_stuff_for_increasing_price, do_stuff_for_lowering_price)
As the IF() statement can check the value of a cell without any extra calculations if it's already TRUE/FALSE. For example, this does the same thing as the above code:
=IF(3F=TRUE, do_stuff_for_increasing_price, do_stuff_for_lowering_price)
So save yourself some extra work in the future and use TRUE/FALSE entries when they're applicable.
Change the single N/O field to just compare installation costs (from the newly updated J column) to make it easier to track and compare in case you want to compare installation costs on their own later on down the line.
Use the same field for P and Q. Keeping it negative is good, as you can do things like =J*Q to find out much you have to increase or decrease your totals, which is a lot easier than reading how big the difference is THEN looking up whether that's an increase or decrease by referring to another cell.
You don't need S, as that's already E. You can probably get rid of T, as your competitors are only showing their after-tax costs, AND you should be isolating the tax variable (as mentioned before) so that you can refer to it later as needed.
After all that, you should have 7 less columns and a better optimized table.
To further refine things, highlight a block's columns (like your Competitor's pricing in E-F) and go into your Data tab, into the Outline group, and click on Group. It'll create a grouping on the outside of your worksheet, where the cell references are, that you can click to hide a grouping of columns/rows. Any cells hidden this way still calculate normally. But that way, you don't need to have your True/False Cost Comparison columns in the way when they're used more for internal calculations than for the user.
Once it's all said and done, it'll look something like this: