Have gotten a LOT less expensive. I just recently replaced a fluorescent troffer w/ a "lenseless" LED troffer. A LOT more light at a reasonable price - and no lens to collect dust. Took all of 20 minutes to replace.
No more worrying about bugs collecting on the lens anymore .
A 2 x 2 troffer runs about $55 and a 2 x 4 runs about $70. They also make flat panels to attach to ceilings if you don't have a suspended ceiling like I do.
When I replace all of them, I will probably change the switch over to a dimmer switch.