1) I would suggest that the images open popup style like here on IIS. The way it loads now results in hitting the back button in order to get back to the item.
For example, click on the image of Saturn.
https://binocularandtelescope.com.au...serving-guide/
2) Also, image size is important. Same link above, second picture is unreadable.
3) Wishlist can be added without logging in, but you can't view a wishlist unless you register and login. Wishlist should be disabled unless you are logged in.
4) Slider for the cost filter disappears when results return no items. Consequently, you have to reload the page from scratch and start over.