Just saw an ad for Home Depot for replacement 4' LED tubes at $14.97 each http://www.homedepot.com/p/TOGGLED-3...g%7CProToggled
Installed 16 of these in 4 four tube troffers. https://www.1000bulbs.com/product/192824/PLT-10848.html at less than $8.00 each, delivered. Glass tube, with plastic protective cover. Frosted. Wire them at one end directly to the 120 v incoming after removing the old ballast. Easy peasy. I have no idea why one would convert over and get the hybrid versions that allow you to leave the ballast in place, heck, half of the light failures are due to bad ballasts. Each troffer went from 120 watts of draw to 50 watts. Plenty of light too. All 16 worked fine the first time. Super double packaging.