By Will Laws Buy or sell? Let’s weigh the options for each of these teams in playoff contentions. Welcome to The Opener, where every weekday morning during the regular season you’ll get a fresh, topical story to start your day from one of SI.com’s MLB writers. We are less than a week away from the trade deadline, but we’ve hardly seen any activity on the transaction wire (the Mets’ acquisition of Daniel Vogelbach is notable but hardly the stuff of fever dreams). That’s partially because the amateur draft was later than usual this year, not occurring until last week, which commanded attention f…