Recommendations for Dedupe Vendors for One-Time Job

Can anyone recommend a vendor who can help with a one-time dedupe project? I have a client with over 10K dupes that need to be merged but they don't need an ongoing service (they've stopped further dupes from being created). The vendors I'm aware of only offer on-going services. Marketo's Easy Merge used to be a great option but they jacked up the price and also re-designed their service to be more of an ongoing thing. We don't have a preference for whether the tool operates in SFDC or Marketo - though it would probably work best if it were in SFDC.