hotel or b and b in London

To help you better it would help to know what you consder reasonable. Everybodies thought of reasonable is different.

We stayed at the Ibis Euston. A few steps from Euston station and about 15 mins walk to St.Pancras and Kings Cross stations.
Price for very comfortable and nicely appointed twin room $143.00US, breakfast extra $12US per person.

Thanks everyone I found a b and b right from the book. all others were booked

Last month we stayed at the Grand Club Quarters Trafalgar Square Hotel in London. It averaged 104 GPB per night (weekday and weekend rates varied). It was very nice. You can see Trafalgar as you walk out the door. Very short walk to Embankment tube and Charing Cross. And it doesn't get more central, as Trafalgar Sq is, I believe, ground zero for distance reckoning in London.

We stayed at Vandon House. A couple blocks from a tube stop, buckingham palace. A great location. Decent breakfast. Room was quiet except for the pidgons outside.

It was an ok place to sleep after several busy busy days. Nothing fancy at all, it is a college dorm during the school year. Clean and comfortable.