You con't need to climb Vignemale. Follow the GR10/HRP direction Baysellance Vignemale then about 1km short of Baysellance you have a choice.
Follow the path to Baysellance then to the Hourquette d'Ossoue (a col with fantastic views of the North face of Vignemale) descend about 1km and then right (east) for the track that takes you over the col d'arraile and onto Estom.
Or at the junction 1km short od baysellance take a right to a lesser used but fairly well trodden track easterly up to the col and lac des gentians (fabtastic views of Vignemale's glacier) from the col it is downhill alll the way to estom passing lots of pretty lakes. This way has less people and more Isards.
Yep. Still using the old rules so booked on line as I do know the date I will be there. 11.00€ a bed and you have to pay 80% (8.80€) in advance, and even if you want to eat and have breakfast it is still 8.80€ in advance.