help learning how to 3D-print discontinued stove knobs

My stove's knobs are breaking. My stove is a discontinued Thermador with range knobs 20-02-584.

I can find replacement knobs (mostly pre-owned) for $65 on ebay. that's crazy high to me for a small piece of plastic, but apparently these knobs have an odd stem that not only breaks easily, but is very difficult to find a "one-size-fits-all" knob replacement. the ebay sellers know what they got.

I've contacted professional 3D printing services to price out a quote, and the cost of scanning a knob and printing it is over $300.

Is there a home solution to this? Could I buy a 3D printer (for $50) and learn to print these knobs myself? I know some of the dimensions will be tough to get right, but I think I could do a "trial and error" print if the costs were low enough.

I've now broken 2 of my 5 stove knobs, so this is becoming a serious concern. frankly, if I break any more knobs and I can't find a reasonably-priced solution, I may very well have to buy a new stove.

Any advice would be appreciated. Thanks in advance!