Help With Sorting By Custom Field

I’ve setup a new WP based real estate site where the property listings are sorting by price (a custom field from the theme). I’m using the wp-smartsort plugin to run the sort. It’s working — sort of. The listings aren’t sorting consistently in sequential numeric order.

Problem: The properties priced in the seven figure ranges are sorting out of order. e.g.: A property that is priced at $1,200,000 will sort BEFORE a property priced at $117,000 and a property priced at $2,300,000 will sort BEFORE a property priced at $228,000 — you get the idea

See it here: http://www.instarvalley.net/categories/8/search_type/and

The sort is set for Ascending – but for some reason it is sorting on the first number in the price string — I think?

Wondering if someone has any experience with wp-smartsort or if there might be a better way to handle this.