1. If the size of the object after uploading to shapeways is different from what you saw in your modeling software, you may have a mixup between metric and imperial units somewhere - perhaps your software has a separate option for export units
2. The "scale" function in shapeways' 3d tools sometimes gets confused when you rescale a model a second or third time.
3. Get the free, cross-platform "netfabb studio basic" software from netfabb.com - apart from checking your model for errors, it can rescale models
4. Printing larger objects gets expensive rather quickly, and 1.3 by 1.5 by 1.5 meters is beyond the capability of shapeways' largest printers. You can find the relevant information ("maximum bounding box") in the design guidelines under the "Materials" tab, where you will also find the cost per ccm.
For quick estimates there is also stonysmith' volume estimator at
http://stonysmith.com/wired/VolumeEstimator.asp