Trump's penchant for grandiose valuation appears most pronounced when he appraises his most valuable courses.
The Trump International Golf Links in Aberdeen, Scotland, is worth more than $50 million even though it had golf-related revenue of $4.3 million last year, according to the filing. Trump Jupiter had $12.4 million in revenue, the Bedminster club had $16.1 million, Trump Westchester brought in $9.4 million and the Washington-area club generated revenue of about $14 million. Mar-a-Lago generated $15.6 million in revenue, and the Colts Neck club produced $6.6 million in revenue. The Turnberry, Scotland, club generated $20.4 million.
Trump's course valuations range from roughly 2.5 times annual revenue for Turnberry to 8 times for Colts Neck, with an average of roughly 4 times revenue.
The courses also look overvalued by other measures. Trump paid a reported $13 million for the Washington club and put $25 million more into renovations, with the revitalized course opening last month. The Bedminster course is valued at about twice its tax-assessment value of $27.8 million, most of which reflects $20 million worth of improvements, according to public records in Somerset County, New Jersey. Beaver Brook Country Club in Clinton, New Jersey, 14 miles away, is on the market for an asking price of $2.5 million.
Trump did not report profits or losses for any of the courses.
Hirsh said courses can be valuable if they're not profitable, but if they're not, they are likely to sell at a level equal to their annual sales—in other words, in line with the industry rule of thumb of 1 to 1.5 times annual revenue.
Read MoreWhat the GOP can learn from Trump
Trump's less-exalted courses have more-appropriate multiples, at least at the low end of Trump's estimates of their valuations. The Charlotte club, which Trump bought for $3 million, had $10 million in revenue, while courses in Pine Hill and Hudson Valley brought in $4 million to $5 million each.
Courses in Los Angeles and Miami have revenue streams other than golf. The Miami course is part of a larger resort and the California business reported $8.2 million in land sales on top of its $13 million in golf revenue.
Golf is becoming a game of scale as larger players and private-equity funds snap up courses, Dugas said. But Trump's self-evaluation is much higher than that of Dallas-based Clubcorp Holdings, a publicly traded owner or operator of 208 clubs that reported second-quarter earnings Thursday morning.
Clubcorp's stock market value of $1.6 billion is almost exactly 1½ times its expected 2015 revenue of $1.06 billion, according to a company forecast. On its balance sheet, Clubcorp valued its property and equipment even lower, at $1.53 billion. The company reported a loss of $4.4 million for the first half of the year, but had positive free cash flow of about $10 million.
Clubcorp bought 50 clubs last year in a $265 million deal and added six more in April in a deal valued at $44 million. The larger deal valued the target company at 2.6 times revenue. That deal value would actually be in line with Trump's valuation of his own courses. However, in 2014, the range of multiples paid for golf courses was 0.4 to three times annual revenue, according to the recent survey from the Society of Golf Appraisers. No course sold for higher than three times annual revenue.