I bought a cheap foldable stationary bike and a stair stepper off Amazon. Neither cost much more than $100, iirc. Both have gotten regular use by my my spouse and I throughout not being able to go to the gym. They're great for making sure you're not watching TV mindlessly. No, I wouldn't recommend them if you want a varied workout, or if you weigh over 200 or so pounds, but for what they were advertised as, and what we needed them for, they were perfect.

Edit: here's the bike https://www.amazon.com/dp/B01N7PO9GV/ref=cm_sw_r_cp_apa_fabc_rHF4FbJ66GN1Q?_encoding=UTF8&psc=1