You could make special foods or give special treats that wouldn't be given often.Or,another option would be to make toys that your hamster will enjoy!
It doesn't have to be anything expensive,as there are some ways to get high quality treats and still save money!I personally always gravitate towards the Higgins brand as they aren't usually expensive but are still really good quality,just make sure to double check any treats for safety
Accidents happen when you think something is safe and is from a relatively good brand,and I have had that happen at least once!
I can't recommend Petsupermarket enough for those in the US.They're almost always cheaper than other pet stores and if you have one nearby or even a bit of a drive away they have some very nice products.I've found things from common brands that you don't find in most chain pet stores,like a wider range than usual of Ware products(lots of nice chews and such)along with a bit of Living World products.
Most pet stores can be worked with though if you can't get to Petsupermarket.You can never have too many spare bendy bridges for example,and those are a good price at Petco for how big they are
It is all about making the most of what you do find,and if you think creatively with limited resources you can always take apart toys and use safe parts to make new toys!