Hi Klarki,
Thanks for the interest. The miners will be shipped from Helena, MT and I can offer them at $275 for purchases of 5 or more. As far as guarantees go, if any machines arrive DOA or have any issues (2 weeks), the buyer can send it back for a replacement or a full refund. When it comes to business, I know that what goes around comes around and I always strive to do things harmoniously. If you'd like to buy them via Ebay which offers a 30-day buyer protection program, you can check out my listing here. The price is listed at $300 to account for Ebay fees. Feel free to message me if you have any more questions.
All the best.