Buy a Roku, and subscribe to MLB.tv instead of MLB Extra Innings. Many cable compnies do not have the bandwidth to provide every game in HD. I had read complaints on this forum regarding all of the out-of-market Sports Packages (NHL, NBA), and what posters have written is that only a handful of games are provided in HD, and they weren't happy about it.
All sales are final, so if you unless you are happy with SD, I recommend you get your out-of-town sports over IPTV instead of the linear feed cable companies will provide. DBS Satellite doesn't have the bandwidth issue.