As others have said, hearing aids fitted by an audiologist almost always have a long return window; if you cannot get used to them, they will take them back for a refund. Expecting to decide whether or not they are sufficiently comfortable while in the office, however, is impossible; you need to learn to live with ALL THE NOISE again, and that normally takes several weeks of consistent use and tweaking. (Seriously, you would be amazed at the roar that can come out of a central AC vent.) FWIW, I have migraines, and my aids have never triggered one; they do bother me a bit because I have a skin sensitivity to plastics, but I have special lotion to ease that irritation. Most BTE hearing aids only have a small nylon bell and thin coated wire inside your ear canal; if you can wear old-style wired earbuds, aids should not be any worse.
Some people actually can't stand the sounds that hearing aids produce because they have gotten used to a quieter world, but newer ones are easily adjusted via a phone app, which makes things much better. (Be aware that very few of these apps work properly on Android phones, so depending on what you buy, you may be forced to get an iPhone if you don't already use one.) Aids from an audiology practice also commonly have a lifetime warranty; the mfr. will fix any problem if you take them back to the practice to report it.
Here's something that was only recently explained to me by a new audiologist: the price grades available in hearing aids are directly based on your lifestyle, and most specifically, if you are employed full-time. Basic lower-cost hearing aids are meant for people who seldom leave their homes, so they almost never are in crowded spaces, and they are used to reading the lips of familiar people. Mid-grade are generally targeted to "active retirees" who get out a lot for social activities, but who don't have to worry about accurate professional interactions too often. Lastly, premium aids are aimed at users who work full-time outside their homes, who take a lot of business calls, and who may need to speak publicly fairly often and/or interact professionally in noisy surroundings. Premium aids interact a lot better with computer devices such as microphones or video-production software, and most new ones will seamlessly link via Bluetooth to any media device you commonly use, switching automatically from one to another (you do have to link them; they don't pick up other people's devices.) Many of the lower-end models don't play well via Bluetooth. Not that many public ALS systems are yet equipped with Auracast, either, but places like WDW will probably adopt the standard sooner rather than later, as it is much less expensive that the previous technology for broadcasting this way ("telecoil" compatibility).
Lastly, there is a cool new bit of technology that is just beginning to hit the market, called Auracast; this is a new bluetooth connection type that allows public performance sound systems to broadcast directly to a whole room full of hearing aids. For a device to support Auracast, it "must support Bluetooth 5.2 or later, and the Public Broadcast Profile (PBP) spec within the new LE Audio standard. " AFAIK, the only brand that presently handles Auracast is ReSound, most of the other mfrs. have yet to update their devices to Bluetooth 5.2 (FWIW, I had to explain Auracast to my audiologist; she had not heard of it. Needless to say, I found someone else after that.)
PS: Also what SirDuff said below. That's obviously the real reason for the higher cost, but I think that most people are told about that aspect when they go to the hearing clinic. I've worn aids for over 20 years (starting in my 30s), and during the earlier sales pitches, no one bothered to tell me that the simpler versions were really designed for retirees. If money is tight, many people will decide they can live without what they think of as the bells & whistles, but SD is absulutely correct to say that, depending on your loss pattern, doing that may further damage your hearing perception because of the effects on your brain of the loss of subtlety. If you're retired it may not matter as much how quickly it goes as long as you have aids to compensate, but in the working world the trade-off is more problematic.
