Renze,
Don't know about shipping costs. Probably not cheap, but it only takes a phone call to find out. I paid $79 for mine a couple years ago, and feel it was worth it. If you spend $30 for shipping it will be the same total cost I had. Don't forget to order a couple replacement grinding wheels.
My personal experience with a Dremel tool (using Dremel's bit, not a Stihl) and a chainsaw file (without a Husky guide) have both been very disappointing. I'm definitely not saying those systems can't work well, but I couldn't make them work for me.
Rather than sharpening dull chains in the field, I carry a couple extra chains, already sharp. If I ever get to where I've dulled 3 chains, I'm ready to quit anyway. Sharpening in the field does have some appeal though. A power inverter plugs into a vehicle's lighter outlet and provides AC current. The chainsaw sharpener draws so liitle power, an inverter would probably power it OK.
Good luck.
OkieG