http://www.thaiairways.com/frequent-...ds-on-thai.htm
and
http://www.thaiairways.com/frequent-...ards-chart.htm
MEL-BKK-MEL in Business Redemption: 98,000 miles + 15,000 Baht - CORRECT
MEL-BKK-MEL buy cheapest economy and upgrade to business: Original Economy Fare + 112,000 miles + 3000 Baht (fuel surcharge difference) - CORRECT
All is correct. It is quite pricey.
(Now please allow other people to come and bash you for flying on award ticket and that you should be mistreated and deserve it too and that awards should cost ideally even more. Strangely this seems to be the tonality lately - I wonder why really)