Stan Lee -- Buy My Mansion and I'll Throw In Spider-Man

Stan Lee is wheeling and dealing ... unloading one of his mansions and willing to sweeten the deal with Spidey.

Our real estate sources tell us ... sure, you can snag Stan's ritzy pad in the posh Bird Streets of L.A. for $5 mil.

Now here's the sweetener ... he's willing to throw in the autographed, life-size Spider-Man statue in the entry, but not for free -- it's $25k extra. The extra cash will go to charity.

Stan snagged the 5,000 sq. ft. house with 5-bedrooms and 7.5 bath for his daughter back in 2012 for $3.4 mil, but she's moved on, so he's cashing in.

Remember, house spiders are good luck.