Once the trademark is registered, you will most probably get a letter (to the squatter) to cease and desist. I doubt the corporate lawyer charges $4k. I doubt a lawsuit is 100% warranted especially when the "squatter" sells or promotes products or services unrelated to the registrants service, or is not selling anything at all.
THis said, I currently own a domain in the (alas final) stages of service trademark registration by other parties. Any day now, I will not have the same rights on the underlying letter combo.
If you or anyone knows of a good strategy to SELL the domain to the future trademark registrants for a profit PLEASE let me KNOW!