Dear wolfy,
yeah i had my share of wow on private servers as well but I am truly a PvE fan so thats why i shifted to wow retail. Now there are two things you need to consider when buying WOW. One is that whether you want the US version or the GB version. Most Pakistanis go with GB version since the time difference between Asian and Europe countries is moderate as compared to that of the US. Also the pings on the GB version of WOW is far better as compared to that of the US version.
Lastly its not difficult to get an lvl 80 character really. I would suggest you level one up yourself. Just about 2 months ago I leveled up a priest within one and a half month. Really you don't want to miss the epic dungeons and lore that is waiting for you on retail. Lastly, you might want to wait a little cuz Cataclysm is just around the corner and most probably a new battle chest version of WOW will be announced soon.