All-Tech Industries pool tables tables were big in the 1960s and early 1970s. It's likely from that time frame.
It's original retail price has zero significance on today's used ATI pool table prices.
The value of these pool tables is all about the exact model, whether it is a commercial or residential model, it's "style". and it's condition. None of which I can assess based on the info you gave.
I can tell you that most of these pool tables are done in a style that is considered very "dated" by today's standards, and because of that, demand is very low. At the same time, folks are selling off pool tables like never before (downsizing, etc). Low demand coupled with high supply generally means low market prices.
By the way, model "8D" isn't the "marketing model name". It's more of an internal model name - and I can't easily use that when looking for it in my All-Tech Industries catalogs without spending too much time.
For example, an ATI-0638WT is called an "ATI Classic" on it's catalog page. I know that mapping because it happens to be one that I've helped identify in the past.
It honestly would be best to post photos of the pool table. If you can't take two minutes to do that, I'm not going to spend 15 minutes looking through catalogs for you.