Hello guys. My friend is currently having a house refurb. He's been quoted for converting vented to unvented. Relocating boiler and cylinder to garage together. Worcester 35cdi system and a 300ltr cylinder.be done in plastic piping with a zone valve to serve underfloor heating(they're not including doing the underfloor heating in the cost though) install nest controls. They have quoted £7k inc vat. I get that it's an impossible question but does that sound like an ok ballpark?