Just a couple of blocks can make a difference of millions of dollars.

For instance, Skechers is walking into a 3,500-square-foot spot at 509 Fifth Ave. under a 15-year deal.

We hear the asking rent was $1,000 per square foot, making this a $60 millionish rent over the life of the lease.

The sneaker company with 3,000 different styles and celebrity endorsers that include Ringo Starr and Demi Lovato, along with NFL greats Joe Montana and Joe Namath, will be replacing Steve Madden on the east side of Fifth Ave. between 42nd and 43rd streets.

Jeff Sutton owns this retail space and handled both sides of the transaction in-house. Sutton, who is making a $1.75 billion bet on the Crown Building farther north on the most expensive corner of the world at 57th Street along with partner GGP, declined to comment.

Just two blocks south of the upcoming Skechers, Muji, the cool Japanese design store, has just leased a 15,500-square-foot duplex store at the base of 475 Fifth Ave. at the southeast corner of East 41st Street.

The asking rent for the 5,500-square-foot ground-floor portion of the retail space was $400 per square foot and when it opens, the North American flagship will also have a massive 10,000 square feet in the lower level. The lower level also has a much cheaper price tag. Based on just the ground floor, the rent will run more than $33 million.

Chris Okada of Okada & Co. represented the company, which already has five other stores in the city, 10 in the US, 500 around the world and more on their way. He declined comment.

Ariel Schuster of RKF represented the building ownership combo of TIAA-CREF and Norges Bank Investment Management in the Muji deal.

But Cushman & Wakefield is now representing the owners for the last available storefront of 4,600 square feet with a new asking rent of $450 per square foot.

An entity of Spanish conglomerate Inditex is finally thisclose to purchasing a retail condominium at 503 Broadway, where it will be moving in Zara and perhaps other brands.

We warned you this roughly $250 million-plus deal was in progress in November 2012. Since then, its longtime family owners, Heng Sang Realty Corp., has divided the building into two condominium lots. Heng Sang will retain one retail space and the upper floors, which could be converted to residential in the future.

Old Navy has long held down the prominent Soho retail location but has just closed.

According to public documents, the Inditex companies will have nearly 42,000 square feet with 13,600 square feet on the ground floor, 13,720 square feet in the cellar and 13,868 square feet on the second floor. Condo documents show the space can be subdivided.

The wide 503-511 Broadway goes through to Mercer midblock between Broome and Spring streets.

According to CoStar information, the remaining retail space is up for lease through a team lead by Joanne Podell of Cushman & Wakefield. E-mails and/or calls to the various brokers, entities and attorneys were not returned.

Stay tuned.

Upstairs at 475 Fifth, companies are racing to get into the newly renovated building, across from the Library and Bryant Park.

We hear that Jay Penske’s Penske Media Corp. is leasing 56,000 square feet for a headquarters office on the second, third, 14th and 16th floors.

The 14th floor has a spectacular terrace overlooking the Library that was being used as a showcase by the building.

The global media company will be consolidating there from both Tower 45 at 120 W. 45th St. and 750 Third Ave.

The son of racing great Roger Penske, Jay lapped up Fairchild Publishing last year from Condé Nast. He now owns prominent media brands that include Variety, WWD, HollywoodLife, various award shows, and his own racing team, Dragon Racing.

Swanke Hayden Connell designed the new lobby, elevators, hallways and bathrooms.

Office leasing is being handled by the JLL team of Douglas Neye, Cynthia Wasserberger, Shawna Menifee, Frank Doyle and Dan Santagata.

Another firm moving to 475 Fifth is VOA Architecture, which inked a deal for the full 12th floor of 15,375 square feet.

That firm will be relocating from the Flatiron District at 27 W. 20th. Greg Taubin of Savills Studley represented the firm. Asking rents there range from the mid-$70s per square foot to the low $100s per square foot at the penthouse.

The parties declined or could not be reached for comment.

Saint Laurent is the Kering brand that will change “middle initials” in February. The store will move from 3 E. 57th St. across Fifth Avenue to 3 W. 57th St. for at least a year while its own store is being renovated.

The new building is the go-to haunt of luxury pop-ups as they renovate their longtime spaces, having been home to Salvatore Ferragamo, Burberry and others throughout the years.

Chris DeCosta and Hank O’Donnell of Crown Retail represented Kering Americas in the deal for 11,100 square feet.

Kelly Gedinsky of Winick repped the building owner, El-Kam.

No rents were available for this area, which is now going for well over $3,000 per square foot.

Old Navy may have closed in Soho but it is opening in Brooklyn.

The retailer just leased 23,000 square feet at 505 Fulton St. along the Fulton Mall.

There it will have 18,000 square feet on the ground and 5,000 square feet on the mezzanine level.

Ariel Schuster of RKF represented Old Navy, which also has a store in Atlantic Center near the Barclay’s Center.

Its parent also has Fulton Mall-area Gap Factory and Banana Factory stores that are doing well, Schuster said.

Albert Laboz, principal of Urban Land, which owns the landmarked former Martin’s store, was represented by Michael Friedman of Inline Retail. The asking rent for large space is $200 per square foot, with smaller stores at $300 to $400 per square foot.