cash or loan?

I am buying a 500K house for rental.  I got a quote ( months ago) for 4.875% 30 year fixed with 0.25 point.  or I can pay cash.  Not sure what I am going to do with the cash now if I use loan.  wait for CD?

If I cash pay, I am thinking to do cashout refi later when the housing market is coming down.  

But I learnt from TZ, for investment in RE, one should always to use loan.   So I am not sure how to proceed.  

Please give me some idea?