Big data applications usually need to rent a large amount of virtual machines from cloud computing providers. As a result of the polices employed by Cloud providers, the prices of the resources have a stochastic behavior. Recently, Spot prices fluctuate greatly or have multiple regimes. Choosing virtual machines according to trends of prices is helpful to decrease the resource rental cost. Existing price predicting methods are unable to accurately predict prices in these environments. Therefore, a dynamic-ARIMA and two markov regime-switching autoregressive model based forecasting methods have been developed in this paper. Experimental results show that the proposals are better than the existing MonthAR for most scenarios.