About 10 years ago, I was together with a LASIK surgeon, one of the best one in the country. He did personally over 150,000 surgeries. It sounds like a lot, but when the LASIK was extremely popular (2001-2002), he was doing up to 100 surgeries per day. So when you choose your doctor, find one who's done many surgeries and has a lot of experience.
I worked in the LASIK office myself, for a year or two (on the side of my fitness business), and I used to be the laser operator. The price depends on what laser they use, some lasers (like VISX) have a special card that doctor has to pay for and it will increase the price of the patient. Nidek laser didn't have this extra fee, so the prices could be lower. Not sure if it is so still now.
Other things came out, like the custom (wavefront) technology which is supposed to be "like a fingerprint" of your eye and make the treatment so much better. Honestly, the regular Nidek/VISX treatment is just as good. For the marketing purposes, they have to promote the wavefront, because the price is so much higher.
I had LASIK done in 2002, just on one eye. The dryness you experience afterward is normal, and I was putting eye drops in my eye every hour or so and I was just fine. Went to my workouts a few days after.
The "life-time" guarantee means that they will do any enhancement necessary for the rest of your life. It can happen, because eyes are changing. After 40+ something, people become presbyopic (hard to read) and will need to get another treatment. I used to go to vision therapy and you can actually postpone presbyopsia with training your eyes. I am 47 now and no signs of presyopsia. When it comes, you don't need to wear glasses if you choose the mono-vision option. One eye for reading, one for distance and let the brain figure it out. It works for many people, some people's brain may never adjust. For athletes, it could mean a loss of perfect depth perception... but you can figure out all this later when the time comes.
I would highly recommend LASIK. It's very safe. If the doctor is skilled, they are hardly ever any complications, other than the patient doesn't listen to the doctor and digs in his/her eye and moves the flap a few days later.
The low prices $499 are marketing to bring the patient in. Very few people get the price (if you are maybe -0.5D or so), but it does happen. Often the price will climb up. You can get cheaper prices in higher performance centers (a lot of patients) because they compete with the "famous" doctors whom you pay $5K for the same procedure.
We are what we repeatedly do... Excellence then is not an act, but a habit.