"If a thing is worth doing, it's worth doing well - unless doing it well takes so long that it isn't worth doing any more. Then you just do it 'good enough'."
Now if they only gave a few pointers on how to find out when it's not worth doing anymore. :-)
In my opinion, the fact that something you wrote will not be around after a year does not warrant a 'good enough' approach.
The point being: if you spend some more time doing things 'right' you'll find that doing things 'right' often means you can do things a lot faster and simpler than doing it 'good enough'.
Think of things like database abstraction layers and the SQL-92 (or later) standard.
Tases time to learn/develop, but once you have it the rest of your development benefits bigtime.
or for ex:
Many people use MySQL because it is quick and easy to install. And then they spend many hours trying to make their script so that it doesn't mess up the database because MySQL has no referencial integrety.
PostgreSQL takes longer to setup, but does have referencial integrety, which means that your script does not have to do intergrety checks and can be a lot simpler, which means takes less time to develop.