Bill, grinding your own lens is sounding friendly but quality lens comes from expensive glasses. BK7 is the cheapest of all but it comes with big sheets and at least transportation costs you a Barnack Leica lens. There are too many old lenses 100 years old around and when they were produced , there were thousands of lens makers. You cant compete with their experience at spherical lenses.

Few ideas you can make ,

A sliding , travelling slide lens for 35 mm panorama pictures.

Cylinderical cut - water jet - lenses for anamorphic record.

Pinhole anamorphic camera which produces 6 x 17 frames.

Multi fractal pattern square pinholes lens sheet which might be corrected at computer but it is faraway better than pinhole , extremelly low f number but records blurry images which must be corrected with same pattern.

3d printing of acrylic lenses if you can handle free lower options lens softwares and produce a stl file and say goodbye to your 500 dollars

Curving a stainless steel thin sheet to a u shape , put a camera in to middle and record UW images.

Inflatable mirror coated film lenses for 500 mm or more

Using a closeup lens filter, attach to a tube and make your tele

Using pinsieves or others , making a ultrawide band spectral camera , using satellite , remote sensing filters , scan multi frames , false color and get satellite pictures like results

Go to zeiss and order one nonspherical lens for 1500 euro etc etc.