I commute on a $5000 road bike. When it rains I ride a $600 single-speed with 75 inch gear. I am about 4 min faster on my road bike because it is stiffer, has a variety of gears and better wheels. (7 mile commute if I take the shortest route.)

My friend at work commutes on his only bicycle, a steel frame fixed gear conversion. (He bought the bike used in 1980's and re-built it from a 10 speed to a single speed.) He has ridden both of my bikes, and his comment that struck me was that he was "surprised" by how much it felt like "All of my efforts were translated into forward motion." I think it is a combination of my bikes being lighter, stiffer, and the lower rolling resistance of high pressure tires. He is now putting bids in on e-bay for road frames. Go figure!

I am convinced that the durability of expensive wheels and bikes is better than low priced ones.

Also, upper end bikes are easier to work on. The only tools I carry for my road bike is a 5mm and 6mm hex wrench.

For me, because cycling is my passion, I can justify top end. But my ride is only slightly better than the $1800 to $2500 range. The single biggest factor in enjoying a bicycle of these price ranges is fit. Seek out a bike shop that has training in bike fitting!

There is "durability", "inexpensive" and "light". You can only have two, your choice. I chose light and durable.

Tailwinds to ya! CS