I have never seen a market for old toilets, nor ever seen one show up on "Antique Roadshow". And because they're heavy and cumbersome, I think you might have a hard time finding someone willing to take it off your property for free.

I do occasionally see them used as planters outside.

my city has a salvage place for old/antique plumbing parts, they are used primarily to restore plumbing in historic restorations

though, many cities do not allow the installation of old toilets, since most new toilets use a lot less water & are much more effcient

many are used as pot plant holders

No, they have a shitty resale value.

Hello,

I've just purchase a house which has an old no longer used outside toilet. The toilet bowl and cistern look very old and I heard someone once say that old toilets are worth money. Can anyone confirm this and how I can find out what if anything it's worth?

Thanks