Great. Now why not make your discontinued back catalogue available for free e.g. the sound packs (often with no more recent alternatives available).
This is regarding the discontinued items like certain sound packs for which no replacement is available (which could be made available for free unsupported), not what they are currently selling. If they aren't being sold then AP aren't making money out of them anyway.
And what would people do if the packs were made free but they did not work as expected. AP would not support them and they would get a bad rep. I don't see any company giving away items that are not on Sale. And AP might revisit them, update and re-release
A better option would be to do what SSS do - they have a legacy section for their older content at a heavily discounted price as they've been superseded by newer content. Having a legacy/budget section for older AP EPs/SPs given they are sometimes still used by content creators would be amazing. Have them discounted to say no more than £10 but offer no official support or updates - they are provided as is at their latest version. However in saying that AP theoretically "could" do it, I doubt they actually would.
If AP were to release their older SPs at a discount price them some people might not buy their newer products The Class 47 SP was used quite well until it was removed If they were to reintroduce it people would have a choice between spending £10 on that or £29.99 on the 47 pack Not everyone wants a pack with all the extra stuff if it affects the way it works
The cheaper option would be good for new players or those who can't afford their newer packs - also, the sound packs at least make the default stock somewhat driveable. Maybe the ones that don't actually have loco packs - say for example the 421/422 sound pack, 303, 442 etc.