Put the two quotes side by side and find the equipment line on each. Write down the model class, the fuel, the controls, and the capacity rating printed on the unit's label. Use the words each quote uses, and ask for the label rating in writing if the quote does not state it.
Check the included parts. Each quote should say whether it includes the line set, the mounting pad, the disconnect, the thermostat, the filter, and the condensate route. A missing part on one quote is a difference, even if the words on the page look similar.
Check the size. A larger unit is not automatically a better unit. The size should come from a load calculation that the installer writes down for the home. Ask each installer for that calculation, and compare the figures on the page, not the claims in the sales conversation.
Read the warranty lines on each quote. Note whether the warranty comes from the manufacturer, the installer, or both, and what the paper says about registration and proof of install. Do not treat a warranty as the same thing across two quotes until you have read both sets of words.
Only after the equipment, the size, the parts, and the warranty lines match should you compare the totals. If one total is lower, ask which line it is missing. The answer is often in the parts list or the access notes.
Finally, place each unit in its planning window. The Heat Pump page on this site shows the service life planning frame for that equipment type. Use that frame to ask how long each choice is likely to serve, and write the answer next to the quote. This site does not rank companies or brands, so the comparison stays on the equipment and the paper.