Anyone have a link or conversion rate for calculating the average salary for the same position in Guangzhou and Shanghai accounting for cost of living?

depends on what you use CPI or some other conversion. However, GZ, Shanghai and Shenzhen are actually pretty close now on the cost of living, in terms of property, food, restaurants etc. I think i read somewhere that it now went Guangzhou, Shenzhen, Shanghai, Beijing.

I just read the Economist's index and it went SH, BJ, SZ, GZ

Many different surveys out there just wondered if there was a general yard stick for approximations.

Guangzhou is still cheaper than other big cities, especially on property, shopping and food. Renting an apartment is around 2000rmb less than a smiliar apartment in Shanghai. Buying one is still much cheaper too but it increases each year and everything tend to me more and more expensive.
Now it depends on the lifestyle, for people who live like expat and only go to western restaurants, only buy import food and stuff, i don't think there is a big difference.
And in term of shopping (clothes or other things), it's simply cheaper because of the wholesale markets (more than 500) all over the city. Actually the city is like a huge supermarket, where you can find everything cheaper than the real supermarket (carrefour...).

Tack on 18.3% and you should be fine... well, a little ahead, but don't worry about the dimes and nickels.

Thanks.