I found it when it was at around $40. Now it's over $230!
Navesink eBay

I see there is another Navesink for sale at a buy-it-now price of $699.

Kind of reminds me of the tricks of an un-named secondary market dealer in Harbour Lights (before eBay).

There used to be a listing service for sellers of various collectibles, including HLs. Individuals could list what they wanted to sell and how much they wanted. This HL secondary dealer would watch what was available and leverage that to raise prices.

Say there were 5 Boston Harbors for sale at the listing service ranging from $60 to $99 (remember, each seller set the price they wanted.)

This dealer would buy up ALL FIVE of the available pieces and relist ONE of them for $150.

When someone called this secondary dealer looking for a Boston Harbor, he would say his price was $139. The potential buyer might complain that was awfully high

The secondary seller would point him to the listing service and say "Boston Harbor pieces are really getting scarce; the listing service only has ONE of them and that one is $150. Mine is a bargain."

I believe the service John is talking about was called the collectable exchange.
They originally dealt by mail then eventually moved to the internet.

My HL dealer use to use this listing as a valid listing for HArbour Light values.I remember one time the Red Letter Legacy Light was listed on the exchange for $1000. At the time there was no other Legacy’s listed.

My dealer started telling his costumers that that was its value. It’s amazing how many Harbour Lights were driven up in value from this type of deception.