2003 Boxster S Price?

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I am new to the forum and just wanted an opinion on the price of an 03 S. The car is listed with a reputable used car dealer and has a thirty day satisfaction guarantee. I had a PPI done by a 25 year veteran Porsche mechanic. He concluded that the car was in great shape and well taken care of. I have decided to purchase the car but would like an opinion on the price.

41k miles
Boxster S
2003
18 inch Carrera Turbo wheels
partial leather
standard stereo/cd, but no door speakers
silver with black top and interior
6 speed
no sratches, dings, dents
interior almost perfect
tires about 40% left
50% on brakes
No leaks etc.
*clean car fax for what it is worth, but no maintenance records

The asking price is $26,995 which is consistent with other 2003 S's in the area. I have always negotiated new cars and never pay close to the sticker. Obviously, this is different. I figure there is at least a few thousand bucks worth of wiggle room here. Any and all advice is much appreciated.