I own a business in Pittsburgh, PA and we did snow removal for a Dentist who rents in the business center where we plowed all winter. He does not own the building, but owes us around $1000. I wasn't sure what lein to file, and if it would be worth it to go through with it, since it is a rather small amount considering.
Snow removal is not really the type of service for which you could file a mechanic's lien. In order to be subject to a lien, the work performed must improve the underlying property. Plowing snow from a property makes the property more usable and accessible, but it represents a more temporary type of improvement which is unlikely to be classified as an improvement for which the installer could file a mechanic's lien claim.
You can sure the dentist in Magisterial Court if you wanted. That might be your best bet for the smaller sum which you are seeking to be paid.