10 years ago I bought a convection oven in a kitchen market.

The place is gone. Anyone know where to get an Electrolux convection oven these days. thank you.

Taobao.

m.1688.com/offer_search/-bfbecfe420bcd2d3c3.html?sortType=pop

tmall.com or jd.com if you can shop online. Otherwise any of the Gome or Suning appliance stores.

You could also try the Boloni flagship store on XiYuan Lu. That is where we got ours. But it won't be cheap, and it won't be free standing.
If you want a cheap freestanding oven, then they sell a few different brands/sizes in Metro. These are much cheaper, but you don't get thermal insulation or a double layer glass door. The cheap ones work fine, but you will need to buy an oven thermometer (about 20-30 rmb, online) as thermostats are not that accurate.

Addendum. Metro North (Beichen) has a much better range of household and catering items than Metro South (Guangfu Lu) which has very little.