You know all the good things for moving her
Main thing is don't clean everything when you move her - it's always tempting to clean everything when swapping cages but best if everything still smells familiar - apart from the odd bit of spot cleaning if there are any wet bits in the substrate.
Definitely try and get a refund. If you are keeping one, it would make a good playcage for when you're doing cage cleans, or could come in handy as a hospital cage some time.
The Hamster Heaven is a great cage - but I agree there are cheaper larger cages on Zooplus. The Alaska and Barney are popular. The Alaska is a little bit bigger than the Hamster Heaven - slightly taller and a couple of centimetres wider and it's only £34. It maybe doesn't look as fun as the Hamster Heaven but then you've got extra money to spent on toys and tunnels for the cage.
The Barney is 100cm cage and a great cage for a Syrian hamster too - and also comes with a good sized house for a syrian. I've just upgraded our Syrian to the Barney from a Savic cage the same size as the Hamster Heaven and it seems just right - it's surprising how quickly they fill up and it can be tricky fitting a Syrian Sized wheel in the hamster heaven. But if you like it, it's still a good cage and has a great front opening door.
This is Charlie's new Barney cage now it's set up - mine has different coloured bars but it's the same cage
I'd check out the Barney cage and the Alexander cage before deciding. I liked our 80cm Savic cage and it seemed big when I got it but I always regretted not getting a 100cm one in the first place - if you can fit an 80cm cage you can usually fit a 100cm one!
This is the Barney on top of the savic cage (same as Hamster Heaven but smaller bar spacing and no tubes)
It's only 20cm longer but is a few cm deeper as well so it gives really good floor space and has a nice deep base for substrate. The Alexander is a really nice cage too and also comes with houses and shelves. Most people paint the wood with plastikote pet safe waterproofing paint. Sounds like a hassle but it's not that bad
Barney Pet Cage | Great deals at zooplus!
Great deals on small pet cages at zooplus: Alexander Small Pet Cage
Zooplus do free delivery and have good customer service. If you click on 'customer photos' for each of the cages you can see different set ups in them - they look a bit plain when empty but it means they are versatile.
Just a few more options there! I found the extra height in the Barney really helped because you could have a shelf level and fit a wheel in easier, and you can fit bigger things in and still have plenty of floor space.