If you want to try the ADS-B receiver, you can do it for < $40. It's out of stoc...

If you want to try the ADS-B receiver, you can do it for < $40. It's out of stock currently, but last year I bought the first one on this page https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

I got busy with other things so haven't done much with it, but there are some Python libraries that made ADS-B easy.