I'm surprised SKB Hamster has had the same experience. When Kiki got her first access I ended up spending over 400 eur as well. This paid for surgery, staying at the vets, antibiotics, fluids, and painkillers. Second time around it cost me around 200-250eur. I stopped counting.
After this and after reading about someone else having this experience, I would just keep setting money aside for vet trips, even if you end up with a stupid amount (as I thought 400 eur was).
About giving the hamster antibiotics, have you tried swaddling them in a teatowel? Sort of maling a hamster burrito and fold the extra cloth under them so they can't back off. Then put the syringe in their mouth at an angle and put the antibiotics in their cheek. With a bit of practice the whole thing takes 10-15 sec (including fumbling with the tea towel) and can be rewarded with a high valued treat.
I found that this works very well for me at least and it's fast which I like, as the hamster doesn't get as stressed. I wish I had to deal with this instead of giving eyedrops to my dwarf who always has his eyes closed. Now that is complicated
