Possession of the matter is the end of the entertainment/fun?
In the Netherlands, where I live, we have a saying:
Het bezit van de zaak, is het einde van het vermaak.
This roughly translates to:
Possession of the matter is the end of the entertainment/fun.
It means that as soon as you have bought your brand new car, it very soon loses its attraction and you don't see the value anymore.
Is there a similar saying in English?
Solution 1:
The thrill is [in] the chase.
It isn't extremely popular, but I think it would be recognized by most English speakers, and it would certainly be understood because its meaning is pretty literal.
The implication, of course, is that the chase (process) itself holds all the thrill, not the quarry.
It draws heavily from popular references to the "thrill of the chase", which is what makes it so recognizable.
Solution 2:
I'm not aware of this idea having a canonical form in English, but the idea is certainly known. A search for "wanting is better than having" finds a great many references, as does "the idea is better than the reality," and might the be best known forms of the saying. The following references from literature and popular culture may be helpful:
Robert Louis Stephenson wrote that:
to travel hopefully is a better thing than to arrive
and Pascal's Pensées (translated from French) has:
we like the chase better than the quarry (#139)
And Mr Spock (of Star Trek fame) said
“After a time, you may find that having is not so pleasing a thing after all as wanting. It is not logical, but is often true.” - Star Trek, season 2, episode 1 (“Amok Time,” 1968)
Meanwhile, Motorhead sang that the chase is better than the catch
Solution 3:
It's not a saying, but we have the term Buyer's remorse, for 'the sense of regret after having made a purchase'.
Solution 4:
Owning the toy is the end of the joy.
...but I just made that up.
If it loses its attraction, don't sell it, because:
You don't know what you have until it's gone.
...which, according to internet, is a common saying in English.