You can buy from a retailer if they have a good warranty and flexible return policy. You can try it before you buy so you can choose a suitable table.
Inversion tables must ensure height and weight. This gives you stability when reversing operation.
Adjustable ankle system for your safety. Provide comfort and assurance that you can keep practicing with them for a long time.
Reversing tables yield the results you desire. You need to invest in your health and life, so choose a table that is worth your money.