As of my knowledge cutoff in September 2021, here is a general overview of the value of this encyclopedia set:
1. Used Condition:
In used condition, a 16-volume set of the Popular Mechanics Do It Yourself Encyclopedia may have an estimated value between $50 to $100 on average. The actual price may vary depending on the specific condition and availability.
2. Good to Very Good Condition:
A well-maintained set in good to very good condition could potentially be worth between $100 and $200. This would apply to sets with minimal wear and tear, no major damage, and all volumes present.
3. Excellent to Like-New Condition:
An excellent or like-new set with minimal signs of usage, no damage, and all volumes included may be valued between $200 and $300.
4. Complete vs. Incomplete Sets:
The value of the encyclopedia set can significantly decrease if it is incomplete. Missing volumes or significant damage can impact its overall value, and pricing would accordingly adjust.
5. Collectible Value:
Early editions or special collector's editions of the Popular Mechanics Do It Yourself Encyclopedia may have higher collectible value and could fetch higher prices.
6. Regional Variations:
Location and local market conditions can also affect the value. Prices may vary in different regions or countries due to availability and demand.
It's important to note that the accuracy of these value estimations can change over time, and it's always a good idea to consult current market data or have the set appraised by an expert for a precise evaluation.