I tried a few date options on BMI ad they were all similar to these prices, what a difference. If you can get a refund I suggest save your money, book BMI and spend the rest in Edinburgh.
departure: Tue 20 Apr 2004 London > Edinburgh
< previous day | next day>
web fare standard fare departs arrives
BD050 11.00 GBP web only 06:50 08:10
BD052 15.00 GBP 20.00 GBP 08:35 09:55
BD054 11.00 GBP web only 10:40 12:00
BD056 11.00 GBP web only 12:50 14:10
BD058 11.00 GBP web only 14:40 16:00
BD060 11.00 GBP web only 16:25 17:50
BD062 15.00 GBP 20.00 GBP 18:45 20:05
BD064 11.00 GBP web only 20:50 22:10
op = operated by another carrier
return: Fri 30 Apr 2004 Edinburgh > London
< previous day | next day>
web fare standard fare departs arrives
BD051 11.00 GBP web only 06:45 08:15
BD053 26.00 GBP 31.00 GBP 08:55 10:25
BD055 26.00 GBP 31.00 GBP 10:35 12:05
BD057 11.00 GBP web only 12:40 14:00
BD059 26.00 GBP 31.00 GBP 14:55 16:15
BD061 26.00 GBP 31.00 GBP 16:40 18:05
BD063 15.00 GBP 20.00 GBP 18:35 20:05
BD065 15.00 GBP 20.00 GBP 20:50 22:05