Hi Chris
I don't like to call these "fake medals" as in most cases although they are purchased not awarded they can only supposedly be purchased by veterans/next of kin(not sure how much this is policed). I like to see them as Veteran/Commemorative medals and find they can add some information on the service details of individuals which without first hand accounts or service files may not be available now or ever, eg Dunkirk/Normandy/Arctic/Malta.
I have provided links to 3 sites where medals may be purchased, you can see the varying prices they attract. The Bevin Boys medal is made of silver and retails at just under £100.
I have also attached some groups of medals with Veteran/Commemorative medals, some with veteran medals awarded by French/Belgian/Dutch towns/associations for service or attendance on anniversaries of liberation etc.
Here is a very useful site for understanding what a lot of foreign commemorative/association awards are: https://www.medal-medaille.com/sold/index.php?cPath=498_63
https://www.awardmedals.com/medals/commemorative-medals/full-size
https://bigburymint.com/commemorative-military-medals/
https://www.empiremedals.com/collections/commemorative-medals