We need to calculate the cost of the trip before we start to <b>plan on it</b>.<br/><br/>Does the above sentence sound right, especially the part in bold? Thanks.<br/><br/><a class='_ac _lb' lightbox='http://forum.wordreference.com/images/misc/progress.gif '><img class='_ac _di img-fluid' style='height:inherit; background: inherit;' data-delaysrc='http://forum.wordreference.com/images/misc/progress.gif' src='http://forum.wordreference.com/images/misc/progress.gif' /></a>