How much to charge for installing a ventilation unit?

I am a builder, who has installed ventilation units before, but always under someone else's company. I am now quoting for my first job as a sole trader of a very simple through the wall HR30W Vent Axia shoe box type heat recovery ventilation unit.
I have a few sparkies in mind to do the electrical side, and I can cut the hole in the wall and make good.

The only question is ball park figure. The client is in Sutton, and the unit is around £190. The job is to supply & install the unit through the solid brick wall, and connect up electrically to the mains via an RCD fused spur from the nearest twin socket, with a 4 way switch (ON/OFF and LO to HIGH speed). Trunking will be exposed.
I would imagine the hole in the wall 2-3hrs, and the electrical 2hrs. Plus time spent do quotation and organising everything.

Can someone give me a ball park total figure for all work, including the unit. I am not VAT registered so I don't need to add this on.

Thanks

Firstly you need a quote from the electrician, you will also want to ensure the electrician will issue the correct installation certificates and issue the notification application if applicable?

Once you have that you can cost for your labour and any materials.
The question is how much do you expect per hour on a job and what do you expect to be paid for supply/sourcing materials?

For example, as a guideline £50.00 for first hour then £20.00 every other hour(your fees may possibly be different), dependent on distance travelled you may consider adding a wee bit on for that?
So I would factor my time on job, the electricians fees (be aware of any additional charges for building control notification), and the material costs, plus anything you add on for supplying.

Ok, I thought I would just throw it out there and see if I got a figure back, but I will clarify. I have actually had a quote from an electrician and I know what I want from the job which is just a day rate of £150. This should cover all the time I've spent organising the thing and installing it. But for just one small ventilation unit, and half a days work it seems silly money. Around £800.
The sparky takes up the bulk of the cost.

I guess this is normally done by a company who will have an in-house electrician who is far cheaper than a stand alone one, and they may even do all the building work aswell. Two tradesmen instantly means higher price.

What would you think is a reasonable price to a customer for the overall job?

I personally was thinking more £500