Anything wrong refinancing immediatly?

[BRadley Cottam]

I am about to purchase a SFHR for about $35,000. I have spoken with my bank and I will be able to immediatly refinance (since im commercial and not personal loan). I will in turn use this money which will probably only be 75% of the 35,000 to either a buy another SFHR for cash or downpayment for a higher priced SFH. Is there a good reason for me not to do this when I can get mid 4% interest rate?