I have an oldish Sanderson breath bike I don’t use. I have had a look around to try and see how much they sell for but can’t find any. Other than sticking it on the bay and taking a gamble, how could I get a rough idea of a price? It’s a 26” steel hardtail, will they come back in fashion?

Try the ‘steel is reel’ Facebook page .

They have a sales page too.

Or Retrobike.

Wait for a free listing weekend on eBay.
Start at a quid and list it with a sensible finishing time.
What it sells for is generally what it’s worth (to someone else).

+1 for retrobike in the post 1998 bikes for sale section. As for pricing, have a browse through there and see what others are being sold/advertised for, at a guess from £100 to £250? The new frames are not that pricey as it is. Sanderson are well thought on there so I imagine there’ll be a bit of interest.