Recommendations for garage finished floor construction 10-15mm thickness?

Hello,

our masonry garage currently has a floor slab as a rough floor. Due to the door/door frame dimensions, the finished floor may be a maximum of 1.0-1.5 cm. I would now need recommendations for a floor structure of 1.0 cm and also 1.5 cm.
As far as I know, the floor slab needs to be ground down. Then there are various floor structures such as bonded screed or leveling compounds, etc.
What would be an inexpensive and simple solution here?

At 1.5 cm: 2 mm leveling compound and then tiles ([Spaltplatten] or [Feinsteinzeug]),

or 8 mm leveling compound and then either concrete paint or 2K epoxy resin coating.

I now have two offers. One includes the full package with leveling compound and 2x coats of paint as well as cove molding etc. Costs: 13k gross (specialized renovation company)!
Other offer: leveling compound Remmer Multiplan SIC, edge strip: 5k gross. However, painting etc. is still missing here (craftsman).

Is the edge strip enough, e.g., for the later plasterer? Or should a cove molding be made and pulled up onto the unplastered wall?

To be honest, I don’t want to have to spend more than 4-5k for the floor with 50sqm – realistic?

Is the edge strip enough, for example for a later plasterer? How should one interpret that? First floor then wall?

Is the border strip enough, for example for a later plasterer? How should one interpret that? Floor first, then wall?

Yes, it currently looks like that...

That makes no sense to me, the floor looks sh... later on -. Cove molding also makes little sense. I would say, sanding, leveling, cleaning the walls and later painting or possibly epoxy depending on the budget.. The floor (floor slab) can actually stay as it is for now??