Last month, the state-run MTA said that it might raise the price of a 30-day subway and bus pass from today’s $89 to $104 — a pretty hefty 17 percent increase. That’s still the case in the MTA’s latest on-line literature about fare hearings, too.

But read the fine print elsewhere. In today’s Times (p18, right below Rick Lazio and the mosque), the MTA ran a legal notice for public hearings with a new option to “increase the price of a 30-Day Unlimited Ride MetroCard to as much as $130.00 and/or introduce a 30-Day MetroCard, priced at less than $130.00, with use capped at no less than 90 paid trips.”

The MTA is keeping its options open, then. While the authority’s goal is to raise total revenues by 7.5 percent starting in January, it could do this in a variety of ways. It could introduce a new “limited” unlimited pass, for example, allowing 90 rides, for, say, $104, along with the higher-priced unlimited card.

Or, it could leave bonuses for pay-per-ride purchases at 15 percent with a minimum $8 purchase, rather than slashing them to 7 percent with a minimum $10 purchase as planned.

To either of these options, though, the MTA would have to hike the 30-day passes by more than it has previously proposed — obviously, as the new legal notice points out, to as much as $130.

The MTA could face some pressure to take this tack and push the unlimited card up further, even if not to $130. Purchasers of the 30-day passes earn more money than people who buy their fares by the ride. The MTA’s progressive fare system, then, could become more progressive.

Middle-class riders should know that they may be in for a bigger January surprise than they thought.

And as I wrote here last month, fares in general once lagged inflation, but not anymore.