Gerald, the closest you can come to cheap AH-meter is a mono-directional gizmo like Watts Up, GT Power or Turnigy. In this order of decreasing price and quality.
Note that Watts Up costs over $50 and still needs shunting and switching the current direction, and is lacking convenience of Cat 5 wire. Adding all this, with the same quality and accuracy, expect a yet to be released clone to cost upwards of $100 delivered to you by slow boat from China, and upwards of $120 if sold through US retailer. Copying/stealing design, tuning up the firmware, getting quality parts, doing QC, warranty costs - this all takes time and money. Maybe this narrow market is not worth it. Hobbyists are happy with $20 meter, and people with big rigs can afford Trimetric or Victron.
PS: Mex, - does yellow fever shot work for Dengue?