When I worked as a 'consultant' (glorified contractor) .Net developer, the company charged > 90 Euro / 105 USD per hour for my time. So that would make my going rate be > 800 USD / day. This is in a country where 50K / year is a decent developer salary.

I do not believe you can find pen testers worth their salt who would cost _less_ than a non-distinctive developer. At least not one who will do more than run some automated report over all your endpoints.