I love the 4.3 but the break-in period kind of sucks. If you are getting nike's under $100 then I recommend getting the Vapors. They're pretty comfortable but like everyone said, durability can be an issue. I tried the Airmax Cages, they're wider than the 4.3's but durability was an issue for me.
I usually play between 2-4 times a week, about 3-5 hours a day at a 4.0-4.5 USTA level. 4.3 usually last me about 3 and a half to 4 months. Vapors, about 3 months. Airmax Cages, (shocking enough) lasted me 2 months.
Hope this helps