Making The Most of Limited Storage Space

I'd like some tips on how I can get the most out of my very limited storage space. I've already pushed most of it to it's limit but want to get more out of it so I can continue building my collection.
I recently finished building new storage racks with a workbench but everything that can go wrong has gone wrong.
The bench space is supposed to be wide enough to fit a 4 foot fluorescent light but I've had to sacrifice much of that space to storing things that wouldn't fit elsewhere. I'd be lucky to fit a 2 foot fixture on it in it's current state.
The underside of the bench is so full that I can't even fit my trash can and stool in the spot where I wanted it.
My fluorescent tubes are stacked in such a way that adding extra parts to the modular racking system isn't possible. The top shelf above the work area is already full of 36 & 40w fluorescent battens, the boxes containing my 2 foot tubes and some other things.
I can't add any more shelves above the workspace because the uprights aren't tall enough. A taller upright for the modular racking I used is available but if I was to use them, I'd have to unstack everything for a second time, take down everything that I've mounted and pretty much dismantle the entire setup in order to use the taller uprights then restack and remount everything again.
I also don't want to get rid of items that still work or scrap functional fixtures because it could cause backlash as some people are very sensitive to that kind of thing.
Any ideas on what I can do that doesn't involve a complete restack of everything?