Finishing the Emergency Stash and Aiming for the Maybach

Before I start, if you're going to use profanity in your username or comments, don't bother commenting. I'll report you.. There's nothing to buy in the Emergency Stash... I already have the regular CEO stuff, so upgrading it seems pointless.. I'd probably buy the Premium CEO if anything.. I'm thinking of buying the Maybach, will it boost my XP a bit.. I'm hesitant because I can't see exactly how much XP it'll increase.. When should I buy the Maybach? It's 450 million..