OP owes his legal team 10 million, which he does not have, and his uncle does not want to pay.
http://www.news24.com/SouthAfrica/Oscar_Pistorius/Oscars-R175m-legal-headache-20141026
He probably does not have a legal team at present who are willing to pursue the matter.
Having said that, appeal is made when you disagree with the outcome - he was convicted of Culp, which is in accordance with his story. What should he appeal against? The sentence? It may be slightly heavier than average, but probably not so much that it's disproportional. The judge was pretty thorough during sentencing.
As for wasting public funds, in this case it is just that. We have just been subject to weeks and weeks of unnecessary trial that should have been concluded in 2 weeks, had the NPA properly assessed the evidence. If OP's bill is 17 mil, then the states cost is probably more than double that. My tax and yours had to pay for that. According to our constitution [section 35(3)m] a person should only stand trial once on accusations [simplified], and I am all for that basic human right. While there are those with a morbid fascination with having OP found guilty of murder, the truth is that this ship has in all probability sailed. Like Paul though I would love to read the appeal and its outcome, but that would be for academic exercise. While you might consider it justice to have a perpetrator found guilt and sentenced to your particular brand of justice, I am far more concerned with equity, which includes consistent conduct from the state [NPA] I personally know of hundreds of cases where magistrates and judges erred in explaining their judgements, sometimes grossly, and the NPA did not bother appealing. Like the trial, which was a piece of showmanship from the start, I am afraid that the appeal will follow the same pattern. Should the state through some miracle achieve a trial de nova via its appeal, all this starts from the beginning with the exception that the state will probably end up paying OP's legal representative as he is without work and without income.