The 4' twin tube fluorescent uses 64 watts and pumps out 5700 lumens of
light, for $49.

The 4' LED version uses 50 watts and only puts out 4000 lumens, for $109.

Are you sure about that wattage?
My LED yard light only uses 18W. Replaced a 175W mercury vapor bulb.
I dont know the lumens, but the LED is brighter.
I'm sure they go on sale at times too..... Plus where are they $109? I'm
sure I've seen them at Menards for much less....

I got the specs and prices from Home Depot:

http://www.homedepot.com/p/Lithonia-...ED-Wraparound-
Ceiling-Flushmount-LBL-4/203839057

It's rated as a "64 watt equivalent", but users stated it used 50 watts.

The same light is available at Amazon for $128, and the specs say 50 watts
also:

https://www.amazon.com/Lithonia-Lighting-LBL4-LP835-
Commercial/dp/B00F94HG54

I chose that light to compare with the nearly identical fluorescent lights
I used in my garage:

http://www.homedepot.com/p/Lithonia-...2-Light-White-
Ballast-Ceiling-Flushmount-LB-2-32-MVOLT-MVIS/202591813

I'm sure you could shop around and find better prices, but you have to
compare the lumen output and color temperature. Cheaper fixtures generally
put out less light, or have different color temperatures (that may or may
not be to your liking).

Anthony Watson
www.watsondiy.com
www.mountainsoftware.com