I am looking at the current generation of drop in replacements, but the simple cost is not a thing easy to get over. A single LED tube actually does cost more than a box of 25 tubes and starters, so to retrofit a room with them would work out to the LED tubes having to last more than 50 years before you get any payback in cost and life, though you would likely only take 8 years or so for the power difference to become equal.
It probably would be better to replace the whole fitting with a LED fitting designed for staying at a low temperature with good heatsinking on the LED dies so they stay cool. You still have a problem with the electronic ballast units being the most unreliable item, and they are likely to die long before the LED units unless they kill the LED by overdriving it.
I have many flourescent units running for over a decade with the original lamps, and a few which are 40 years old and are still running the original ballast, though the tubes do need to be replaced every 5 years or so. The advantage of paying more for tubes with a reputation of long life, as opposed to the buying of the cheapest on the market.
