Hi Raymond
Have a look at the Practical Caravan Homepage (click HOME PAGE in the blue rectangle under the logo)
Navigate to the
Caravan Finder and enter your requirements, budget, postcode etc into the box and adverts featuring caravans which may interest you will be shown. I saw about 4 t/a caravans within your price range when I looked just.
Practical Caravan magazine also has a classified section featuring used caravans for sale.