Wholesale House or Purchase as Investment Property

[Casey Cook]

I am in contract with a multi-family investment property for $470,000. This property is on a 3.3 acre residential lot. The lot has a main house (4 bed, 2 bath brick rancher), a detached In-law suite (bedroom, bathroom, kitchen, living room), a detached guest house (studio with bathroom and kitchen), a 31'x39' detached 3 door garage, a tennis court (in need of resurfacing), and an in ground pool (in good shape). I will treat it as a house hack by living in the guest house and renting out the main house for $2,350 and the In-law suite for $800. 

I've been informed that there's another buyer who is willing to offer $490,000 and my agent said we could probably do a wholesale and make the $20,000 difference. Is it a better investment to make the quick profit and look for another property or hang onto this property and make more money over a longer period of time?