Waterline/Perimeter Tile: Most pool dealers charge between $1500-$3000 to tile a fiberglass swimming pool (on the waterline). Retaining Walls: Retaining walls can get very expensive, and depending on the size can obviously vary a huge degree.Most walls cost $5000-$15,000.ool Lights: Most pool lights cost between $700-$2000 Although all of these numbers and prices are very general, I do hope this article helps you to have a better feel for fiberglass pool pricing and what to expect when you start going through the pool buying process.