Actually, from what I understand, Texas as a whole actually isn't low cost for HVAC. Extremely high demand and all. I don't really want to give a guess since it would be specific to our particular market. Recommendation: if you want to save money get your system replaced during a time of year when it isn't especially cold, hot, or super humid. Roughly February, right? HVAC contractors will be more competitive on prices just to keep themselves occupied. When your AC goes out and it's 110* you're going to pay more. Hire a real company to do it. We hate having to charge someone a good chunk of money after they only just paid an underskilled someone the year before who really shouldn't be in the trade. See it all the time. Last week we had to charge someone for work that he'd only had done a few weeks before by someone else.
Don't buy into the high-efficiency push. The components are much more fickle, and the manufacturers keep changing them every six months it seems. If they break once it'll cancel out all the savings from your 10 year break-even on utility savings. Manufacturer warranties only cover parts not labor, and the more complex systems that look so nice and small are much more difficult to get at the parts. Eventually the average HVAC technician will need to have gone to grad school for electrical engineering and computer science. More and more circuit boards. Systems really aren't made like they used to be all in the name of government-mandated efficiency, and the rise of "The Internet of Things." When someone calls with a 25 year old system that's still chugging along and they ask what it'll cost to replace, we tell them a ballpark so they can start earmarking money but also frequently suggest they consider waiting until it breaks. These are usually people who we've been regularly servicing for decades. Maintenance truly does make a difference.