In Germany most newer carts take 50ct, 1€, and 2€ coins. The older ones took 1€ (or 1DM before the introduction of the Euro). Abandoned carts on the premises aren't much of a thing anywhere I lived except for maybe the odd lazy person with a plastic coin in it (some.people carry those around e.g. on their key chain for when they don't have coins on hand).
And honestly, if there was two euros going for simply moving a trolley back to its parking zone, I suspect you would have shoppers who found it worth doing that for all of the free carts, let alone people with less money coming in to collect.
What I more often see than carts with coins lying around is people straight-up stealing the carts. If they live in nearby streets they just push the cart home and then use it to carry or store stuff around the yard.
You can see several such carts in the streets surrounding supermarkets.
