It depends what you mean by decent condition. If the top needs replacing, that's an important - and expensive - item, so the value would be reduced accordingly. Body condition, modifications, any problems with the car, maintenance records.. all of these must be considered. But 1971 is the last year of the early bumpers, and that makes it a desireable year.
Bear in mind that the prices in The Samba's classified ads are
asking prices, and people often ask far more than the car is actually worth. It is amusing, and those ads are good for entertainment purposes only. But yes, if you read a few pages of ads on The Samba, you will get a general idea of the car's value.
edit: you could always post an ad on The Samba asking the price that you would
like to get, and see what kind of responses you receive.. ignoring the numerous low-ballers, of course.. and then change your ad if necessary. Better yet, you should ask this question on the Karmann Ghia forum on that website.
