The Ferplast Duna Multy is an option. About 70cm by 45cm - a bit smaller than the Hamster Heaven.
https://www.portonaquapet.co.uk/shop...a-Multy-M36261
If you can find a used Hamster Heaven that is a good option too. Better than the Alaska in my view as it's lower. The Alaska is also an option but there are fall risks for dwarf hamsters so it would need setting up really carefully.
Or if you could stretch to it, Zooplus sell the Hamster Heaven for about £50 (best used without the penthouse and tubes as a straight cage). It comes with plugs to block off the tube holes.
It's actually £64 on zooplus at the moment but it's usually £50.
https://www.zooplus.co.uk/shop/small...r_cages/197362
You can often find second hand Hamster Heavens on ebay quite cheap though.