The Dakota is very nice but miles out of town.
The Premier Inn at Edinburgh Park is a good balance between cost and location IMO. It isn’t in the city centre by any means, and whilst that means that there is nothing much nearby, it is literally right next to a tram stop, from where you can be in the city centre in 15 minutes or so for £1.70. There’s also free parking.
Premier Inns are perfectly decent properties l, if not flash.