On 25/11/2019 03:37, Bill Wright wrote:
Prices for a 33V 1A psu as used by stairlifts to charge the battery.

Typical Amazon price: £18
Farnell: £26
Medical grade item: £76
Quoted by a stairlift supplier when a replacement was needed: £181. Item
is tiny and in a plastic case, and appears to be poor quality.

Price for a carbon brush, ditto: £25.

Bill

The same happens with batteries for burglar alarms. Mine needs
"replacing" periodically. At service, they offer one for £x. Looking
online, I find an identical one for £y. Guess the differential and in
whose favour :-)