For some products, there is little or no room for maneuver in pricing. Vendors buy HVAC components from manufacturers and may not have a way to obtain them at a lower price. However, not every negotiation has to be about getting the lowest price per item. Discuss the quote with the HVAC contractor and ask if there is room for negotiation.
Be respectful and polite, but don't hesitate to ask for a better price. Some companies may be willing to negotiate to win your business, especially if they're competing with other companies for the position. Be sure to communicate your needs and budget clearly and see if there are areas where they can save you some money. However, keep in mind that not all HVAC companies are willing to negotiate their prices, and you decide if their quote is reasonable and fits your budget.
If the HVAC contractor isn't willing to provide you with an all-inclusive quote, it could be a red flag that they're not a trustworthy company. HVAC dealers get different price discounts from equipment manufacturers, so the best companies could also offer you best deals.