Non Payment of invoice- Seek recovery/filing a lean

[tony fox]

I have a customer who has not paid an invoice fully. Services have been rendered, job complete. Invoice submitted in the amount of $3,100.00. Customer only paid $2,296.84. Balance amount is $803.16. Job was terminated due to high level of interference with the
construction process, which was delaying production schedule, ergo, profit margin. Approx. 3 weeks since part. payment. Re-invoiced with a Sept. 1st due date.
Questions;
A. Is this worth pursuing?
B. If so,whats next step?
C. Anticapated cost of recovery?

Thanks !