Can you give us the engine model and type number? There may be a B&S or aftermarket muffler that would work for less coin.

Unfortunately you may not have many options.

Your motor is a 287707-1257-E1.

The special 7071939 muffler may be the only one which fits and clears the gas tank. Standard Briggs mufflers for the 287707 include the 495805, 496022, 495882, and 498984 and generally cost from $45 to $50. You have limited options because the muffler is flange-mounted to the engine head. Best bet would be to see if shop would loan you one of the standard mufflers, or allow you to return, after you dry fit to see if it works.

Unfortunately the later OHV Briggs are much less forgiving because the muffler is flanged to the head. The old L-Heads had threads in the exhaust port, and you could use several pieces of black pipe and elbows to connect to cheapo aftermarket muffler.

Good luck.

Dak: Ebay may be your only quick solution. Otherwise a Local Welding Shop Specialist can fab up a muffler assembly for your unit if you bring the mower to their shop for proper measurements to alter the cheaper aftermarket muffler to your flanged fastening requirements. Pricing would likely be half the price of the new OEM Muffler .