We have not really seen a decline in people wanting to buy over rent but we do have the same phenomenon where people will call more off a rental ad than a for sale ad.
Our biggest strategy is that when they call to rent we tell them that the rental amount is say $550 per month. We then also throw out the option that we will sell the same home on a RTO or Lease Option for $500 per month. So we give them an incentive to buy over the incentive to rent for all the normal reasons including the lower monthly payment. This has been the most effective strategy we have used.