Ok, sure, technically. To be fair you can't really assess the opex of technology that doesn't exist yet, but I find it hard to believe that operating brand new, huge machines that have to move fluid around (and not nice fluids either) will ever be less than it is on the surface. Better hope you never get a coolant leak. Heck, it might even be that opex=0 still isn't enough to offset the "capex". Space is already hard when you're not trying to launch record-breaking structures.

Even optimistically, capex goes up by a lot to reduce opex, which means you need a really really long breakeven time, which means a long time where nothing breaks. How many months of reduced electricity costs is wiped out if you have to send a tech to orbit?

Oh, and don't forget the radiation slowly destroying all your transistors. Does that count as opex? Can you break even before your customers start complaining about corruption?

Maintenance will be impossible or at least prohibitively expensive. Which means your only opex is ground support. But it also means your capex depreciates over whatever lifetime these things will have with zero repairs or preventive maintenance.