3 metre long plastic cloche from Wilkinson cost £7.99
Product advertised in Kitchen Garden is £18.99, and looks identical.
Even at 8 quid they're not the cheapest form of cover, but very convenient, and with care will last a few seasons.
However 19 quid??
It probably is identical. I use Poundland cloches; they're pretty small but they're OK for trays of seedlings. Didn't see any last year though.