My experiences are very different.
I've found walking through a room with LED lighting the strobe/flicker tends to be more noticable than Fluo.
Most of my work has been commercial and it's not uncommon to have dozens of fluo lights on a single circuit, as a tube fails they tend to get replaced with LED, no according to your statement those LED tubes will not need replacing until all of the fluo have gone, I can say without fear that I've known LED versions to be replaced 2, 3, 4 times before all of the fluo have gone. Added to that; the total myth that LED light level doesn't drop, wherever does anyone get that silly idea from, go into any office with LED tubes and replace one. Expect to be amazed at the difference between between a new and an old at 5000 hours and also don't be surprised if LED don't last a whole year when on 24/7 but I would be surprised if a fluo fails, plus of course a fluo will swarn of failure with fading, light/dark patches, take longer to strike etc for a while but LEDs tend to have a sudden full stop.
I simply get my supplies from wholesalers, generally I don't get to pay any published prices but most things of an ilk will have a similar discount, so stating: 36W flou 3350lm = £3.06, 18W LED 2165lm = 7.85 directly from www may very well be closer to £2 and £5 (plus VAT)