Sanity Check an AC install Quote for me?

Hi All.

Im looking for a sanity check for my AC install, as im fairly sure my quote is pretty overpriced, but I wanted to double check.

This is the tech they suggested i get fitted :

1 No.4MXM68A9 Multi Split Outdoor Unit

1 No.Stylish CTXA15CW Wall Mounted Indoor Unit Serving GF Office

1 No.Stylish FTXA35CW Wall Mounted Indoor Unit Serving GF Living Room

1 No.Stylish CTXA15CW Wall Mounted Indoor Unit Serving FF Bedroom 1

1 No.Stylish FTXA25CW Wall Mounted Indoor Unit Serving FF Master bedroom

The install is in a 4 bed detached house, the heat pump and all 4 internal units are along one external wall and all in trunking on the outside of the property, so as far as im concerned a fairly straightforward install (they confirmed that it seemed straightforward to them).

The breakdown they've now given me is:
Daikin AC Kit:                                                                                 £3,900.00

Materials including pipe, cabling, Trunking, Fittings:  £2,982.00

Portable Scaffold Hire                                                                £375.00

Power supply for AC                                                                    £1,200.00

Labour including travel + fuel:                                                £3,788.00

To be the actual AC unit price seems fair, the materials price, labour and power supply prices all seem excessive?

There is room on the board for a new spur that will just run externally to the units, so no big work there.

I kinda feel like they pulled a figure out their ass and now i asked for an itemised breakdown, they knew they couldn't fudge the AC kit too much so the rest they have just massively bloated.

That being said, im not an electrician so what do I know, hence why im asking you :)

Any help appreciated, i also appreciate AC is somewhat not entirely in the remit of electricians so understand if you arent sure.