It really depends on your requirements.
Is it okay if the car has a different color on the outside, and if the edges around the windows aren't perfectly clean, then taping will suffice.
However, this is only recommended for truly old cars (e.g., repairing and restoring a rusty car that's over 10 years old).
It looks neat if you remove all the trim pieces and rubber seals.
"Perfect condition (like a new car) is extremely expensive because absolutely everything needs to be removed."
As a rough estimate, you should budget around €3000 for a reasonable (i.e., mid-range) paint job, including the paint itself.
It's crucial to thoroughly clean and roughen up the old paint; don't cut corners here (because if you rush, you might end up with a new coat of paint that peels in places, revealing the old paint or primer underneath, and you'll have wasted your time and money).
Everything else looks like a complete mess due to the lack of working time and the resulting inability to disassemble parts.
Doing it yourself would be the cheapest option if you don't need your car for two weeks, have enough time, and already have some painting experience. If you've only painted small parts before, it's probably not recommended; you shouldn't necessarily start with the most challenging project.
If you consider your golf to be in the "under 1000 Euro car class" (although that doesn't sound very appealing), then this would be a good way to practice and gain experience.