Hi Ian, perhaps you could try this address www.norfolk-greenhouses.co.uk they have a variety of different types of G-houses. Sorry that I can't post that as a link but I don't know how to, (computers aren't my thing) best of luck.

Not sure what you call cheap. It is pretty easy to find second-hand glass/aluminium greenhouses, say 8x6, for around a hundred quid on eBay. You could also check loot.com and similar online classifieds, same sort of thing if you wait long enough, sometimes cheaper. Local classifieds maybe even less, occasionally free, but you might wait six months.

If that is still above your budget, freecycle occasionally has greenhouses to collect, but not often and usually will need some repairs or replacement parts.

Flexible plastic greenhouses don't come up secondhand very often because, frankly, they don't last long enough! They start with the three or four shelf type at around twenty quid, to small walk-in ones at around fifty quid. Expect a couple of years use before the plastic needs replacing. I'd only go this route if you're not sure this hobby will last, otherwise shell out a little extra cash for something more robust.

Try Aldi. They usually stock the frame/cover type during April/May which apparently last a couple of years, at least. Maybe Lidl too.

Certainly agree with shrubs about the longevity of flexible plastic greenhouses. Also in a strong wind things get knocked off the top shelves. I use one but only because i can't find a rigid one the right width (5ft). they're all 6ft.

Hi,

Have you tried FreeCycle?
This is a web page for people to recycle stuff like green houses, Its free! I have seen greenhouses on there in the past(Normally free to collector).

http://uk.freecycle.org/

Hope this helps!
Moolarman

Here is a link that might be useful: Moolar Gardening Tips