Need an online calculator for custom stained glass and mosaic panel pricing

We are looking for a developer to build an online cost calculator for custom stained glass and mosaic panels. Our workshop takes orders for church windows, decorative door inserts, garden panels and interior mosaic murals, and right now every quote is worked out by hand over the phone, which slows down replies and leads to different managers naming different prices for similar pieces. We need a widget for the website: a visitor enters the panel dimensions, chooses a manufacturing technique (Tiffany copper foil, leaded came, hand-painted glass, or mosaic assembly from smalti and glass tesserae), picks the design complexity (geometric pattern, simple floral motif, or a detailed pictorial scene with shading), selects the material grade, and optionally adds installation and framing.

The pricing logic must combine several cost drivers rather than a flat per-square-meter rate: technique changes labor time dramatically, complexity multiplies cutting and fitting hours, and material grade affects both cost and lead time. We also want the calculator to suggest a realistic completion period from the same inputs, since a large pictorial window takes far longer than a small geometric mosaic tile.

Requirements:
— input fields for width and height in centimeters, with sensible min/max limits
— selectable manufacturing technique with distinct price coefficients
— complexity levels (low, medium, high) affecting both price and lead time
— material selection (standard glass, art glass, smalti, natural stone) with price impact
— optional installation and frame checkbox that adds to the total cost
— live price range and estimated production time shown instantly on input change
— mobile-friendly interface with a button to submit the calculated request as a lead