There are billions, billions, of nature runes. This will have the smallest - not even note worthy impact. Once jagex starts creating serious sinkholes that cost a few million GP at a time things will have an influence on the economy, and even then it will remain small. The enormousity of the amount of GP fluctuating around is uncountable, this has been so for years already. Nice try perhaps, to create a 'sinkhole' perhaps - but IMO if based upon that point of view, pretty much failed.