Go to the Lapidary Equipment Marketplace on FB. Loads of used equipment in good condition for sale. I’ve gotta let the cat out of the bag and say: lapidary is NOT a cheap hobby! Look into a Genie or Pixie by Diamond Pacific. Very good company and some of the top tier wheels in the market. Some would say they’re the best.
A flat lap would be cheaper, but it’s not quite the same as lapidary Diamond wheels. Also, check FB marketplace and Craigslist for lapidary equipment. Since Covid prices have gone up because people are staying at home and developing hobbies like lapidary. A lot of places are out of stock for new. Anyway, hit those three places I mentioned and good luck