Ain't he referring to an ad of 2013?
IMHO, the XP Boost is an expensive path with little impact, unless (now) you have a massive CDP bonus at stake. But, remember: you pay for points of no own value which are designed as a grind for levels and equipment that again costs you money or currency.
In your situation, it looks like totally uncalled for. Be aware that XPs are a tool to reach the dangling carrot and get equipment, and you are in good shape!
And if you want to help your CC, there's even less to gain. They have the basics, Putter and Shot Pals. Your owner left the building AFAIS, participation is dwindling and in-CC activity may be close to nought.
My two Pfennig: Save your credits for clubs, balls and fun!
On a different note: Shape your friends' list down to 255 - the system is out of order for the excess!