We sell some cars each month from the 3rd party lead providers we use, so it's tough to just stop when there is some ROI there.
However what I've started to do with our BDC is develop processes to better work manifest/equity lists (formerly given to salespeople).
I believe that with a proper action plan we can close those prospects at a similar rate to the 3rd party leads. I guess the thinking behind it is if my team can properly work say 800 new leads per month for example why not cut the 50 I buy and replace them with free prospects from manifest lists, then my marketing director can use some or all that money in ways that will give us more prospects that close at higher percentages.