Austrian gold ducats are amazing coins. They have been produced for centuries (up to this day) and always command strong values. This page applies to ducats issued by Austria's Franz I, who ruled from 1745 to 1765 with his wife Maria Theresa. Inscriptions on these coins read FRANC D G R I S A GER IER REX (king's identification and territory) and TU DOMINE SPES MEA (You are my hope, O God).
Genuine Franz I ducats are worth base value (BV) when worn or damaged, but climb in value as condition improves. To compute BV, multiply the weight of the coin by the price of gold. These ducats contain 0.111 troy ounces of gold, so BV today is about 0.111 x 1306 = $145 US dollars. Tomorrow's value of gold will be different than $1306 per ounce, so look it up at kitco.com.
Coins not worn are worth more than BV, as follows:
average cirulated: BV + $200
well preserved: BV + $400
fully uncirculated: BV + $600
Apparently it was not that long ago that Reader's Digest magazine ran a promotion and produced a bunch of replica coins that look like Austrian gold ducats. Most have a date of 1752. Some carry no date. You can see an extensive discussion of this coin on CoinTalk.
Genuine ducats are things of elegant beauty. Counterfeit ducats are worth zero. In the comparison below, check the overall crisp appearance and intrinsic appeal of the genuine coin from Stacks Bowers to the mushy and lifeless appearance of the fake.
Especially in this day and age of high-tech counterfeits, is it absolutely necessary that any serious collector deal with fully reputable, nationally recognized coin dealers.