You could make a bin cage
It's a plastic storage bin and you cut the panels out and attach mesh to the panels with cable ties, if you don't mind a little bit of diy and know someone who can use a hot knife. The 78cm Samla bin from Ikea is quite cheap at about £10 (plus the cost of the lid I think which is maybe another £3). It's the biggest bin Ikea do. It's still not as big as 80cm by 50cm but it's not a bad size and has the height to fit a syrian sized wheel. So if obtaining cages is difficult where you are, then a bin or basic diy cage might be the way to go.
You might find a plastic storage bin that's slightly bigger than that. The detolf is also from Ikea, but it is quite long. If you have space for it it makes a good tank with plenty of space. You just need to make lids out of wood and mesh.
As the others say your cage is small at about 2' by 1'6" approx - but it is difficult if parents won't allow anything else. You might be able to get them interested in helping you with a diy project though.
Does your hamster seem happy? And does he get much out of cage time? Or does he bar chew and look miserable and get aggressive? They do need a lot of exercise, particularly at night (hence needing a wheel), but some, especially older hamsters, are ok with a smaller cage. I would try and get something slightly bigger though.
An important issue is wheel safety. Not sure what wheel you have, but i know wheels are hard to come by in some countries, and open grid wire ones are dangerous. The wheel needs a solid running surface. And to be at least 8" or more in diameter for a Syrian. 11" diameter is a good size.
How old is your hammy?
Here are some examples of bin cages
https://www.google.co.uk/search?q=ha...w=1525&bih=630