You know, quite a few people have returned Pets at Home cages saying it's not suitable/big enough, after getting something new, even when it has been used, and got a refund. It is worth a try. If not then a spare cage as a play cage isn't a bad thing to have - eg when doing a clean out.
Upgrading the cage would be a good move - but - cage changes are also stressful for hamsters and they need time to settle in a cage, so it's probably best not to do it straight away. Usually it's recommended to give them a good two weeks to settle into a cage, without any clean outs (just spot clean the pee area once a week maybe by taking a handful or so of substrate out and replacing it with a clean handful and mixing it in a bit. Or just emptying the litter tray if you have one - they will pee in a litter tray
If you put it in the place they have chosen to pee in.
So it's probably best to leave your hammy in the current cage for at least 3 or 4 weeks before upgrading. Then there are methods for upgrading that make it less stressful - moving everything across without cleaning anything so it still smells familiar, including all the old substrate, and in a similar layout - then another 2 weeks settling in period. I find an adjustment helps as well - rather than cold turkey - eg let them play in the new cage with some substrate and a couple of toys in, the day before moving them, or even do that twice. And then move everything over - it does seem to speed up the settling in process.
The tubes on that cage aren't good either - external tubes cause issues and hamsters can get stuck as well (full pouches or just growing very large!).
Zooplus has some good options at reasonable prices. Popular ones for Syrians are the Alaska, Barney and Alexander cages, depending on how big a cage you can fit in and your budget. The Alaska cage is about £35, the Barney about £54 and the Alexander about £69. Out of those the Barney is the best value really as it comes with a good sized house for a Syrian and a good shelf and has a basic 8" wheel which would do for starters (anything smaller than 8" diameter is too small and can lead to back pain). So there's nothing really to buy extra - just needs substrate adding and some toys/floor tubes etc. You may have some already but cardboard tubes and hidey places are fine. (Rat sized toys work best for Syrians).
However the Barney is also the largest of the three - slightly deeper floor area than the Alexander. The Alaska is a good budget cage with a good sized floor area - however many people find they want to upgrade from it later to a bit more floor area. It also needs a good house/nesting box buying and a wheel.
I have the Barney cage. I started out with a horrible 3 tier rotostak - and our hammy got stuck in a tube and had cage rage. He was upgraded to something the size of the Hamster Heaven (also on Zooplus) but without all the tubes and Penthouse. At the time I kicked myself for not going for a 100 cm cage as our Syrian grew very large! And his large wheel, toys and houses filled the cage too much. So eventually he was upgraded to the 100cm Barney, which seemed just right for him, and I could fit loads of things in and still have plenty of floorspace, plus the extra height meant any large wheel would fit in. But not too high either(there can be fall risks with very tall cages).
The Alaska is a bit better than the Hamster Heaven in that respect - maybe not as well made as Savic cages, but has a bit more height and width. Delivery is free from Zooplus when you buy a cage, so anything else you buy at the same time will also have free delivery - otherwise delivery is extra when buying things from there.
https://www.zooplus.co.uk/shop/small.../hamster_cages
They sell a couple of good syrian wheels. The 28cm Trixie plastic wheel is popular and inexpensive. It's not silent but most people find it quite quiet. There is also a wood 28cm Trixie wheel with a cork running surface. This is a silent wheel (has ball bearings), but does need painting with plastikote (petsafe waterproofing paint) or it gets stinky. The best Syrian wheel you can get - and it is good - is the 12" Silent "Runner" (not Silent Spinner - different wheel) which is also silent and can be cage mounted to the bars - but it is quite expensive - £25 plus another £5 for the cage mounting. That's only available from a couple of sugarglider shops/sellers.
Pets at Home also sell the Savic Hamster Plaza which is a 100cm cage - but it does cost £75. It's good because it has a big front opening door but is a bit taller than the barney so needs setting up carefully to avoid falling on something hard.
I have the Barney cage - theSavic Plaza wasn't available when I got my cage but would be my first choice now - except for the cost!
The barney and Alexander cages have narrow bar spacing of 7mm which means they can also be used for dwarf hamsters, if set up carefully to avoid fall risks for tiny dwarf hamsters. 7mm bar spacing means they are less likely to bar chew as well, but most hamsters don't bar chew in a 100cm cage.