The $10 entry fee is equivalent to about $92 today. The prize fund in today's dollars is about:
$150 = $1,385
$115 = $1,062
$85 = $785
$60 = $554
$40 = $369
It should be pointed out that the Eastern Open was a major Open. The Carolinas Open was more typical of a weekend Swiss:
The $3 entry fee was the equivalent of about $28 today and the $2 membership fee added another $18.50 to the entry fee.
This chess clock was quite small and it was the kind that was used in the world championship matches. Cost in today's dollars: $166.
And the very nice Windsor Castle chess set cost between $97 and $182.
Of course playing in a weekender also meant hotel costs. One old timer wrote that they remembered that in the mid to late 50s they drove from Ohio to Florida every year. That was before the interstates were built! They spent two nights in family-type motels on the road getting there and the room costs were usually $12 or $14 ($110-$128 today).
So, things weren't so cheap back then. The minimum age was $0.75, or $6.92 today and the average income was $4,137, or $38,200 these days. According to the U.S. Census Bureau, the average household income was $73,298 in 2014, the latest year for which complete data is available. The median household income in 2014 was $53,719, which means that half of American households make less than this amount, and half make more. Since the median is significantly below the average, it tells us that there are more households with below-average household income than above-average, and that the average is distorted by a small percentage of high-income households. That $53,719 median today would have been the equivalent of half a million back in 1955.
There were a a few chess clubs in Ohio back then: