There's also a direct bus to the centre of Dongguan priced at about $180 per pax. I don't know where the golf-resort is, but my educated guess is that the most expensive taxi fare within the Dongguan area would be in the region of 50 yuan.
BTW, I find it really bizarre that someone would fly PVG-HKG then go back and cross the land border when they can catch a flight to SZX which is much nearer to Dongguan in addition to being within the PRC.