I'm currently charging the car off the mains plug with the charging cable that came with the car.
Always overnight and the app tells me it's 9h 44mins for a full charge (~35km). This costs me 3,50EUR (£3.15).

I know that with the proper chargers installed at home it charges quicker, but presumably the cost of charging would stay the same (3,50 EUR)??
A charger will set me back around 750 EUR plus installation and no government subsidies to be had.

Other than improvements in speed of charge, is there straight up further financial gain? - other than being abelt o charge quicker and therefore more frequently.

cheers 2019 RRS P400e Autobiography
2014 RRS 3.0 TDV6 HSE Dynamic
2006 RRS 2.7 TDV6 HSe
Alfa Romeo Guillietta 2.0 JTDM 2011
Mazda 3 1.6 2010
Subaru Impreza 2.0 WRX 2005

When you put it like that, you don’t really need a fast charger at home.
I don’t know if your cable is built to be used daily

We have at least 60A house hold supplies. Maybe that is why we like them

This guy fits them.

I've not got any form of electric vehicle, but for charging batteries of any sort the no.1 killer is heat. Fast charging creates heat, and although with lithiums it's been promoted that they are less affected by fast charging but it's now creaping out that they are also affected in a big way, giving much shorter life - a person may well think it'll last their usage lifetime before selling on/handing back but it will slowly start being noticed as less capacity which increases running costs as they take the same or more electricity to charge. And this all has a negative impact on the environment which I expect many electric vehicle buyers are thinking of.

If I were to go electric, then I'd certainly be planning a long slow charge, but some folk probably cannot manage to do this. For now, I'll stick to my diesel.

As a side note, for anyone with solar panels or wind turbines then have you checked out the chargers at https://guide.openenergymonitor.org/integrations/ev-charging/ ? Years ago before you could buy them, I built a system on this sites forum guidance to divert unused solar electricity to my water immersion heater, and they now do the same with diverting unused electricity to the car batteries which means genuine free charging. 13MY Range Rover Sport Autobiography SDV6 - mine
14MY Range Rover Evoque Dynamic SD4 Black Pack - wife's
99MY Defender 90 TD5, Soft Top Conversion - my toy, and bairns favourite

I think Tesla's only charge up the amount required, (with a bit of margin), rather than a full charge.

I only charge my iPhone to 80%

Most BEV will only go to 80% on a “super” charger - more than 50kWhr - then the charge rate tails right off. My PHEV takes only 3 hours on a domestic 13 amp plug for 26 miles range, but it also has software to limit the charging rate to a max 7.2kWhr to avoid damaging the HV Battery. At home the MaX charge rate without a 3 phase supply is something like 22kWhr. I’m about to place a reservation on the new Tesla Y and to charge that on my domestic supply would take 4 days....... but new tech for Tesla is water cooling of the battery as they are now looking at 250kwhr charging - about 35-40 minutes to add 300 miles range on one of their susperchargers but heat pumps are essential for decent battery life. I’m quite happy with my low charging rate at home / on public chargers as I charge at home overnight and plug into a free to use public charger in the park and ride in the local town. I also don’t need to use my car every day so in the case I know I’m not going to be using it I set the charging rate down as BMW’s system in the Mini has 3 charge rate settings. Even with the Tesla with 320 miles electric range I would only need to do a full charge quickly if I wanted to do a very long trip away from home. 320miles electric range is 10 days motoring or more at my current journey distances so the car would easily get a full charge while I am shopping. I’m able to use my Countryman PHEV in pure electric mode so much that in 22 months I have only needed to visit a Petrol Pump 10 times....... a full fuel up with petrol doesn’t take much time either with only a 35litre petrol tank. 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

I upgraded from 3 pin domestic to a 7KW 32A charger. I do not have a driveway so I have to trail cables under a cable cover over the pavement (sidewalk!), meaning I don't like leaving my car charging over night.

I am extremely happy with my solution. It charges to 99% very quickly (2 or 3 hours), then to 100% within 4 hours. Dunno why the last 1% takes so long! As soon as I plug in I hear a fan come on inside the vehicle somewhere, which I do not remember happening with the old 3 pin domestic method.

It's an eo-MINI EM002 and cost about £400 exc. fitting. It's delightfully tiny. I installed additional circuit breakers and such for safety.
https://www.eocharging.com/eo-mini
They also do a 'Smart version', the Pro, which comes with an app etc but I had no requirement for that at all.

 L405 P400e Autobiography (MY2020)... Silicon Silver / Espresso
RRS TDV6 HSE Lux (MY2011)... Nara Bronze / Arabica - now gone!