Geez the guy or gal just wants a plain answer not the other vitriol found on the other posts.
As an FO the only ticket upgradable to Bus is the annual leave ticket locked to your nominated home country for 3 years after which can be anywhere on the network, but not upgradable for kids below 13(??) You have the option of buying for yourself and immediate family unlimited standby or firm tickets to anywhere on the network after probation. SYD return DXB econ standby is USD240 incl taxes. Bus USD500. Firm econ USD 650 and bus USD1300. Firm tickets on availability but outside peak times (not school hols and northern hemisphere summer) generally ok. These also apply to extended family on your approved list you can avail 2 standby and 2 firm tickets at the same price. There are also special tickets which aren’t really that special as almost the same price as found on some bucket websites for the econ tickets. Business are a much better option if they have the bucks as way cheaper than on the market rate. 12 (??) of these a year can be given to any friend or family member.
All your tickets of course need the time off to be usable!!
good luck