Is Mobil 1 THAT good? Is it OVERKILL to use synthetic oil for the intermediate?

[dainese]

Hi guys,

I want to pamper my R32.
She has 61000 kms, and I was thinking to get some synthetic oil for it.

I am told synthetic oil lasts longer. And I know this to be true.
But do you think it may be overkill to use it at the intermediate service (in this case 7500 kms)?

I am a mechanic by trade, but we were only taught how to make them money. And they only used semi-synthetic Magnatec.

Where is a good place to get cheap synthetic oil?

Thanks,

Justin