Q. AT&T’s site doesn’t let me select any plan for a new phone but their unlimited option. What happened to the cheaper plans with limited data?

A. Browsing for wireless service plans at the Dallas-based company’s site has gotten a lot more confusing in recent weeks. AT&T’s page listing its menu of data plans has at times only shown the two unlimited-data options it rolled out at the end of February—and if you begin a phone purchase online, you’ll only see the two unlimited plans.

That might not matter if you know you’ll use a lot of data (keeping track of that can be tricky in iOS) or if you don’t want to have to worry about exceeding a data cap. Otherwise, AT&T’s older Mobile Share Advantage–starting at $50 for 1 GB of data on a smartphone, with $60 for 3 GB likely to cover many people’s needs–represent a better bargain.

Fortunately, AT&T isn’t following the practice of T-Mobile and Sprint in selling only unlimited-data plans (which might be better called “unmetered,” since they still feature some restrictions). Brett LeVecchio, AT&T’s director for global media relations  says new customers can still get the older, cheaper plans over the phone (888-333-6651) or in its stores.

Current subscribers, meanwhile, can still switch to one of them online. AT&T didn’t explain the reasoning, but an industry analyst says the most likely explanation is AT&T favoring its own stores as a more lucrative sales channel.

“When they get you in the store, they typically get to upsell you somehow,” said Roger Entner, founder of Recon Analytics. Maybe they’ll convince you to pick up a charger or a case; maybe they’ll persuade you to pick a more expensive plan than the one you had in mind.

In comparison,…