You'd want to order one bag at a time,otherwise you'd take a risk at the food going bad even if frozen.I think if you could get a shipment set up for when you should run out it would be nice,but at the same time it may last longer than you expect so perhaps figure out how long a bag lasts but before the last few weeks of food are used up order a second bag(you can do this by measuring exact amounts out and portioning them into the smallest possible plastic bags or containers).
If you can find a way to get small portions of vegetables that would be helpful,but if not the next best thing is frozen thawed vegetables(except with some vegetables and fresh foods that need cooking like any sort of potato and for other fresh foods beans would need cooking too).It isn't always easy to find a local farmer's market or produce stand,but when you can it's always nice especially if the produce is in some way better than regular supermarket produce(such as non-GMO organic produce,and the minimal carbon footprint of something grown locally compared to things shipped from further away when applicable)!
Mealworms are in the Burgess,but dwarf hamsters generally love mealworms considerably more than Syrians.I've tried two types of dehydrated chicken cat/dog treats myself(Pure Bites and Simply Nourish,with the second being exclusive to Petsmart)and those are very good.It's equally nutritious as raw compared to cooked meats,but luckily the process essentially eliminates concerns of salmonella(not really a concern if the food is handled properly and the animal in question is omnivorous or carnivorous by nature with a healthy immune system).
You can get a lot of different freeze dried meat treats from Chewy,along with quite a few other wonderful things(their small animal section isn't that good,but the dog and cat sections are almost perfect and luckily quite a bit of that is safe for hamsters).
I can say that of the biscuit selection Chewy offers I know at least Sojos and Chicken Soup have diabetes friendly hamster safe options,however they're fairly different in price.Of course,Sojos is more of a human-grade product than Chicken Soup which makes a huge difference with pricing,but I would still suggest Chicken Soup!I'll definitely try and make a list of diabetes friendly biscuits from Chewy though
I also forgot to mention that unspecified fat is also an issue,which shows up quite a bit(mostly with lower end foods and treats though,but still not acceptable even in "high end" but low quality foods).