I wonder if there is a way to do this without using any modules. I can't seem to figure this out. I just want the regular_price + tax + shipping.
Shipping is calculated on a per-order basis, so you can't show what the shipping cost on an individual item is (once products are added to the cart, you can calculate the shipping for the whole order).
To display prices inclusive of tax, open Settings > Taxes and click on your tax rate, then click "included in price". You can then enter product prices inclusive of tax in the control panel, and these will also be displayed on your website's front end.