I've got a De'longhi machine at home, there are various prices depending on how fancy you want it to be but there is not a vast difference between them all other than the milk frothing. It's my third one and if you want one with all the bells and whistles the mid-range ones seem like better value. They are all pretty large though.
In our holiday home I have a "Beko Bean to Cup Coffee Machine CEG3190B". This is a plain black version which is around £150 and is fine. It's very basic, you can change the grind, or the amount of water to suit a large or small cup.
It isn't huge and has very simple controls.
This machine doesn't froth milk but you can get one of those electric milk frothing jugs relatively cheaply and I actually use one at home in preference to using the De'longhi frother which is a pain to clean. Or you can simply warm milk in the microwave in your mug before you add the coffee.
There's a report about bean to cup coffee machines on Which.co.uk and the Beko comes out as "Great Value". Another slightly more expensive one has a milk frothing wand.
I often buy electric appliances on Amazon, from the Warehouse deals where they have a damaged box or whatever. Or sometimes from Ebay where almost everything is cheaper - though I try to buy something which is marked "new" or "new other".