Retail?

Yeah, both the price at the time of purchase and current one should be mentioned.
Some people do confuse the issue in their ads and also sometimes inflate the retail prices but not necessarily intentionally.

If you're selling, for example, a 1967 tri- power Corvette for $100K tell me how the original purchase price is an issue. As a prospective buyer, I could care less.

At the end of the day, isn't what you pay all that matters?

Guess we need a "Price Police", not going to happen. The current new price, original price, or what someone actually paid to a dealer are all considered retail. Should I buy a used piece of equipment, and know the price is fair, compared to market value, bluebook, sales history, etc, what difference does it make as to the listed retail by the seller? I am more concerned with condition and history of that particular unit. It makes no sense to even list the new retail for a used piece of gear. If you buy a used car, or anything else, does the seller list, or quote a new retail price?

The retail listed should be when the seller purchased the item. Some sellers are very sensitive if you ask the date of manufacture of a component.

Another vote for current retail as that is what it cost to
buy a new one now. And at the bottom of the deal, people
very seldom pay the asking price. So what does original MSRP
matter, value is determined at the point of sale.As long as
they aren't providing an inflated false list price, in my
opinion no harm with current list. If you are looking for
Boraxo Model F250XE Amp, you know a little about it and
probably what it sold for. Now records are a different story.
The add should state a 4.99 album new at Woolworths is now
20.00 for NM.