The best places to buy or sell second hand teasmades are eBay, Gumtree, Freecycle, apps like Shpock, or car boot sales. You can also buy and sell teasmades on Facebook.
Beware of false claims of rarity or age. For example the Hawkins Classic is often advertised as Art Deco! There are not many collectors so prices are not generally inflated, but you’ll pay more if you buy before Christmas!
Common models from the late 1960s to the 1980s sell for between £5 and £25 depending on condition. Models from the 1950s and early 1960s fetch £25 to £75. Pre WW2 models may go over £100, and the very oldest and rarest may command well over £200.
Sheridan is not currently buying teasmades.