the last time i looked, j was $7-8k for dfw-mel w/around 18k mi's, which irrc is about the cost of an around the world j fare. you should be able to route the rtw for more mi's and see a few places if you have the time...

however, you don't provide enough info to get a specific answer...

what are the end point cities.....what alliance or airlime are you looking for....

good luck....