budget slider when there is no "do nothing" option entered

[josephrbennett]

When there is no "do nothing" the budget slider seems to default to the minimum cost of all options as the "0%" value. This could be confusing. We could deal with via manual (i.e., by making sure people are apprised of the importance of entering a do nothing option), but anchoring the budget slider at $0 and maximum possible might be a better idea?