Hi, to try and save you some money, you may want to look at my playlist for run ideas for hamsters-
https://www.youtube.com/playlist?lis...nMw9Ro6wJO-zmU
some of the shop bought ones are easy for hamsters to escape from and not worth the money. the simplest and cheapest thing is a big cardboard box, but it will most probably need replacing at some point when your hamster chews his way out! So, yes never leave your hamster alone, or you will have a fugitive on the loose.
Also hamsters can spend quite a bit of time grooming themselves, especially when they have first woken up or been upto mischief running around somewhere.