Cardio Vascular Procedure Required

I'm a 70 year old Australian man requiring the replacement or sleaving of a stent which was inserted in Australia in January of this year and has now failed.
The stent was inserted into my left upper leg but pain experienced over recent months prompted me to have CT Scan in Chonburi public hospital which revealed the failure.
Unfortunately, there is only one public hospital in the region which has the the facilities to carry out such a procedure and although I was scheduled to have it done around 6 weeks ago, the quoted price had more than doubled on the day I was scheduled to have it done from 250,000 to 520,000+  so because I was unprepared for this, had to opt out.

I'm now anxious to find another hospital or doctor to carry out this much need operation but need to have an accurate idea of the cost before hand so I can have the funds available on the day.
I would be most gratefull to anyone who has had a similar situation or if anyone has any information which might help.
I live in Pattaya but am willing to go wherever is necessary to have it done.