I don't know what the regular mail insurance limit is in the US, but suspect it will be aligned with this country where the maximum insured value is £250. Over that and you are using a courier (including Parcelforce) which is considerably higher, or if you have separate insurance, you can send it regular mail. Prices can escalate. If I want to send a higher value thing to the US with a courier, the price is in the £30 area, but can be more depending on value. For imports from the US to me, $30 is a minimum charge whichever auction house it comes from.
They won't send it on a wing and a prayer as they are responsible for it getting to you, so arses will be covered.