I'm reminded of the quote by Hamish Mahaddie the pathfinder.
He went to Buck House and was wearing the ribbons IIRC of a DSO, DFC and a foreign award and this at the stage of the last unpleasantness before campaign medals were generally in issue. Afterwards, he and others adjourned for some refreshment and he was asked by a lady what the medals were, he was wearing. He claims to have replied: "I've no idea madam, they were on the uniform when I bought it".
As to the cost of medal mounting, one needs to compare the exceptionally smart arrangement of medals 'court mounted' against the scruffy 'loose mounted'. Even a single medal mounted in the former style shows a pride in appearance, whereas the latter (and occasionally seen in the wrong sequence 'cause it was left to 'er in doors to add them to a bar obtained on eBay) suggests a certain disinterest and lack of pride - rant over!
I am well past my three score and ten but still taking the shilling on certain occasions. However, I have no expectation of anything further to be added and so am unlikely to need to spend anything on mounting - mind you, the cost of Brasso's creeping up!!!
Old Duffer