I'm no expert in pushchairs, and even less so on double ones, but just a quick Google of 'twin pushchairs' brings up a host of options with not a single price tag under £129.99, except, of course, this BabyStart Twin Pushchair from Argos.
This pushchair does tick all the boxes I think a parent would care about too. It's suitable from birth to 3 years, and has a two-hand umbrella fold. It has multi recline positions, and forward facing seats. There are five point harnesses, and lockable front swivel wheels with dual wheel suspension and linked brakes.
The handle sits at 102cm high and it has an adjustable leg rest.
Included in the purchase is a shopping basket, detachable hood, and chest pads for comfy restraining.