Baffled by Pricing Strategy

I have also witnessed this phenomenon on other sites.  One in particular, is an amp that has been for sale for about a year,and the price goes up and down about a grand. I don’t get it,but hey, who am I? 

I noticed on Ebay that if I lower my price, I lose a watcher or two! It's happened many a time...figure that out! I've often raised my price back up, only to gain watchers! Lol, people are freaking weird. Sone of those same items eventually sold, at the higher price....

Possible strategy to deter low ballers and tire kickers.
I’ve not had one occasion where I wouldn’t accept a fair offer or my fair offer would be rejected by the seller irrespective of asking price.

I’ve raised a price on an item, typically within one hour of posting if I feel I listed it too low. 

I’m not sure what others’ strategies are, but I can see a few reasons:

1. At the time of listing, there are perhaps other similar listings that are priced lower. If they all sell and only one is left, perhaps the seller thinks they can make more money since there isn’t any more competition. 

2. If it is a current model, perhaps manufacturers recently increased the retail price, making the used price also go up. 

Maybe believers in the fallacy that more expensive products are better. Kind of like some companies won't allow their stuff to be "on sale" because it supposedly cheapens the brand.