Its virtually impossible to implement such a policy.
There are those who stick to the known routes up the mountain, and due to inexperience or unfamiliarity with the area, would not dare leave their chosen route.
Most of us would not like having to pay, yet more money other than the often costly car parking charges around the mountain.
Could we be absolutely certain that the extra revenue this would generate, would be spent on maintaining the area.
Does Gwynedd Council use the revenue generated by the parking charges, and many yellow parking tickets they issue, to maintain the paths up Snowdon ? i somehow doubt it.
Personally i would not mind paying say a £5 note, to do a particular route, if i was 100% certain that money was being used for path management.
The revenue needed to maintain the routes up Snowdon, is considerable, and must come from somewhere.
I would not begrudge paying towards their annual maintenance, therefore safeguarding them for future generations.
The thing that worries me, is such revenue may be used elsewhere, and possibly wasted on pointless ventures.
You could easily fence off the entire summit area of the mountain, install several gates, and charge an entry.
A step to far, but if that payment was guaranteed to be spent on path maintenance, and nothing else, i personally would not mind paying.
I am sure there would be countless thousands who would not pay, that's their privilege, but are they climbing the mountain for other reasons.
Its there, and the erosion caused by millions of feet, is not their problem.