Maybe Madonna's (search) "Re-Invention Tour" needs a little retooling.

Thousands of tickets are still available for the Material Mom's six-night stand at Madison Square Garden (search) that begins tonight — many at cut-rate prices.

Late yesterday, Ticketmaster, the official retail outlet for Madonna concert tickets, had seats in all price ranges ($50 to $300) for all six nights.

And some ticket brokers — who usually offer seats at a premium — were desperately trying to clear their bloated inventories with discounts of up to 30 percent off face value.

"We're losing money on these tickets," said one broker offering deep discounts. "The bottom line is she's doing too many shows."

Besides the six MSG shows, the 45-year-old musical artist has two shows slated for Continental Airlines Arena across the Hudson in New Jersey next month as part of her 19-city world tour.

"Tickets are selling well, but not as well as anticipated," said Michael Issac, president of broker Preferred Ticket.com. "Three years ago was a much stronger tour."

That tour, "Drowned World," (search) "was a whole other ballgame," Issac said. While his agency isn't discounting tickets for this stand, the last tour drew prices "five times" the current stand.

A broker at greattickets.com said the phone was ringing off the hook, but not for Madonna — for the NBA's Detroit Pistons, who are close to winning the league championship series from the Los Angeles Lakers.

"Her public opinion might be shifting," said the broker, who did not want to be identified.

A few brokers remained optimistic yesterday, offering $300 second row center seats for tonight for up to $1,700.

And a $300 front row center seat for Sunday's performance was offered for $2,400.

Front row seats for tonight may not be available through Ticketmaster, but as of last night, $300 tickets on the floor in Row L were available for face value plus the usual processing fees.

The show was initially reported sold out, but last week hundreds of tickets were released as more seats became available after the stage was set up.

Liz Rosenberg, Madonna's publicist, said she's not worried.

She remained confident that tonight's show will "absolutely" sell out.

"A lot of people know that last-minute tickets are available," says Rosenberg.

She's doing well nationally. According to Pollstar, the first 10 shows averaged $2.6 million in ticket sales, selling more than 136,000 tickets over 10 shows in four cities. The average ticket price is $175.

The tour is on track to be the top-grossing tour of 2004, with a gross in the $120 million range and attendance of about 920,000. "New York has always been an exceptional market for Madonna," says Gary Bongiovanni, editor-in-chief of Pollstar. "It's hard to believe she's not selling tickets. It could be she held back tickets, and people are just finding out."

Meanwhile cable channel Trio TV is having a little fun at Madonna's expense, hosting three Madonna silver-screen bombs at the Loews Theater on 34th Street.

The schedule: "Who's That Girl," tonight; "Body of Evidence" next Wednesday, and "Swept Away," on June 29.