[phoenix n max]

I have to get to Heathrow from midlands on 1st Feb. I looked into driving and leaving car but i'm away for a month and thats expensive in airport parking.
Looked into trains but means going from here to New Street and then on to Heathrow and that ain't cheap either.
Looked into one way hire - hmmm !
The only coach co I can find is National Express and the schedule is less than perfect.
Cant ask my Dad or Son as I consider it too far for them to drive and Jase is working anyway.
Does anyone have any other suggestions for travel from midlands to Heathrow thats not going to break the bank ?
Put it this way - i'm staying in a 5 star hotel in Dubai for less than it's going to cost to travel to airport so far.
Any of you good people got any good ideas or links I can use please ?