I look on the GumTree website (out of nosyness, I'm not looking for new fur babies, honest boars)
They have loads of young and baby hogs.
Some of them are obviously breeders (by the way they 'word' the adverts and the fact they might have several litters on offer). They might be asking £10-£25 per piglet (or less per pig if you buy 2).Some will actually state that they won't sell a singleton unless you have a piggie already.
Then there are the ones who are moving/new baby/new job/ new cat or dog
Some are just getting fed up -or the DC are - and they want rid of the pigs.
There are new ones posted every day, you might need to travel.
TBH, I wouldn't pay them the money they ask.Some will ask for a 'commitment' (ie ££) from a new owner. But I could get a brand new pig for £20, so unless it was a Rescue, I wouldn't pay an owner who wanted a good home. The commitment of a home would be what I would give them. Might pay for a cage though.
Breeder v Private Owner? You get more reassurance from a responsible breeder.
(And as for the owner -about 6 miles from me- who wanted someone to go and pick up his daughters GPs while she was at school and knew nothing about the GP going.
Advertised as "Would make a lovely present" .

for the GPs being booted out as a lovely present "for a child"
for his DD coming home to find her pet gone
And what happens to the GPs if no-one takes them?