$35 80-200mm Lens
The amazingly sharp Nikkor 80-200mm f4.5 AI-s lens adapted to an APS-C sensor (120-300mm) is stunning.
This lens is one of eBay's best secrets. Regularly selling for $40 and can be hunted down at $20 with ease I adapted it with a K&F Concepts adapter for my FUJIFILM X-Pro 2. The adapter is $12.99 from china on eBay making this set up is manual focus perfection for a total of $35.
There are a few different versions of this lens but the best one has a distinct difference from the others, a black rectangle on the rear element. The only poor feature on this lens is it has focus creep due to a very loose zoom element. If you start carrying rubber bands you'll be a happier person, though I've only used one once.
Being a 30+ year old Nikkor it offers superb film like rendering that isn't difficult to process to get a more modern look. I should also mention this is one of nikons smallest and lightest high zooms they ever made.
It doesn't get much sharper, definitely not at $20
Zoomed all the way to 200mm (300mm) on my camera. Since I got this lens it has been a permanent addition to my camera bag, why not? it doesnt take up much room.
Nice sunstars too.
Not silly to put on an expensive camera, It's so inexpensive it is incapable of being silly. You could buy an extra for parts (I did) or a third just to take apart (I did) Nothing wrong with wanting to know how a great piece of art was made, buy it and have fun.