Lynn, these are now 59.00 as costco ....amazing and give off tons of light ,about an inch thick https://www.costco.com/skylight-flat...100526320.html

I like these but wish they were more in line with the 4' fixtures price wise.

They do have a 4' model that is about 1/2 of that cost if those work for you. I put the 4' version in an unfinished storage area of my basement and they work well in smaller areas. When I was looking it seemed most of the LED's I saw were the 4' version and when I found this fixture in an 8' model it was perfect for my application, I agree not inexpensive but I only needed 5 of them.

I would like to change out a 25,000 sf building with them. but don't want to spend that much to do it. kinda defeats the purpose of the money savings energy wise.

Around here the electrical utility company (ComEd) has generous incentives for LED lighting upgrades that significantly shorten the payback on a building that size - not sure if something like that exists where you are, but maybe worth checking into?

Just as everyone else, I replaced my 4' fluorescent bulbs with LED last year and love it. I have a 30 x 40 shop with 12 ceiling light fixtures. I did have to bypass the ballasts and left off the lenses to keep the dead bugs and dust from gathering in them.

LED's 4 foot in 5-6k color temp...
They put off about 5000 lumens.
I am converting my paint booth to LED next.
FROM 10- (4 bulb) 4 foot fixtures to 10 (2 bulb) 4 foot fixtures.

FWIW -
A standard 4 foot (4 bulb) florescent will put off about 8000-8800 LUMENS using the correct DAYLIGHT bulbs. (2000-2200 per light bulb)

2 - 4 foot DAYLIGHT LED's will put off 10,000 Lumens.

converted all lights
 

This place beat all the places I looked at converting to LED


https://greenlightdepot.com/

I was looking at the lights in my shop today and I now have 8 of the 20 8 foot LED bulbs that are only 1/2 working. I wonder if there is a way to get the other 1/2 to work again.