Within the expensive Amalfi coast, we found the Locanda Degli Dei a great, affordable option.
Praiano is a great base from which to explore, if you have a car. The B&B is in a great location for this also - a lot of places are halfway up a steep flight of stairs, where as the Locanda is at the top of the hill on an accessible street, so you can park right out front.
It's 10-15 mins walk to the centre of town (down lots of stairs!), and only for the fittest would I recommend the walk back up. But there's a local bus that costs 1euro which drops you right out the front of the B&B.
The Locanda is simple - nothing too 5 star or fancy - but has everything you need and is clean, and nicely decorated. It has outstanding views of the water, and a gorgeous garden from which you eat breakfast enjoying the view.
The staff are authentic and delightful, and really helpful with organising tours etc. if needed.