I can offer a couple of comparables:
The following is for sale in this month’s Old Bike Mart:
Scott two speeder, 1925, nice order and has rare combined fuel/oil tank, offers on £5,950. Tel. 01274 595229 no canvassing.
and Ron Farthing has a 1924 2 Speeder advertised on his site for £7500 at:
Hope this helps you decide!