I have a Vario, that has struggled with a fine espresso grind. The burrs are ceramic but the carriage is plastic and it affects the tolerance. I gave up repairing/troubleshooting it and bought a beat to hell SuperJolly off EBay for $170.
Dropped in a new set of burrs and have an unstoppable overkill grinder with a huge motor and all metal parts
If you want espresso you probably want steel burrs mounted in steel with good bearings.
If you are on a budget and don't want to spend £500 ($700 + tax and shipping) on a niche then you can usually find used smaller commercial machines. Research the burrs they use and see if you can find new burrs, this way you can spend probably somewhere around $200 on what would function like a brand new high quality burr grinder.
Dropped in a new set of burrs and have an unstoppable overkill grinder with a huge motor and all metal parts