Dollar for dollar, business class awards are generally a better bargain. Depending on your destination, you'd spend 70,000 points for a $1000 ticket vs. 120,000 points for a $5000 ticket. As for economy vs biz it all depends on your tolerance level. Some airlines have decent economy products. I flew between SFO-SYD in economy a few years ago and vowed not to do it again. My back ached for two days.