Back in the mid 70ts I remember seeing quite a few pink demos kicking about usually priced up between £18 and £20 never saw an issue - 

an issue went on e bay for about $550 just curious what the demo would make today ?

cheers 

Demo is commoner than the issue. Hard to value either at present as the chase is on to collect Top 500 classics at any price. Neither come to market frequently anyway so expect the price to keep rising. Even the UK 70’s release fetches a nice sum these days. Good tune and one that was huge at Wigan hence the continued interest in the record.

£300