Shaun you should be fine with $3000 over 10 days. I would personally allow $3000 for expenses after your plane ticket just my 2 cents of advice.
You will be buying food, probably for her and her friends, and most definatly the family if that is in her arrangements (Most expensive meal I paid for was 400RMB and that was for 10 people! Damn worth the money too!) just for my girl, her friends and I meals were around 30rmb-160rmb depending. Paying for any trips you take, for example my LONG tour of China for her, a friend and I cost right around 5500RMB that was with 6 (18) flights, (75) every meal, 10 parks (most parks were 50-100rmb entrance fee included in tour price), bus rides, tour guides. This was all covered in the tour package. Sometimes I would have to pay an additional fee here and there say the spare bed fee at some of the hotels but it was 100rmb and it was reimbursed daily. There were a couple of parks not included on the tour some we went on others we didnt.
I highly suggest having her make your hotel arrangements, otherwise you will pay tourist prices, around $100+ to $65 a night, she can get them down lower, $55-30 and even cheaper. You can take advantage of most of the hotels breakfast, personally the breakfasts always sucked so I insisted we go somewhere else. Noodles and Dumplings for the win!
The translators through the agency I used, I asked how much I owed them, when it was an all day thing I paid around $10 an hour because I thought it was fair. Then again Nanning is a lot cheaper than say Beijing. An electronic translator is about $300 here in the states, have your girl take you to an electronics store and barter one down got the newest Besta for almost $200.
Then trave expenses, taxi's typically start on 6rmb or 7rmb +1 additional rmb fuel surcharge. This gets you a kilometer or two so after that its a time and miles +1 RMB fuel charge. Then there is traveling by bus for 1 rmb, there you can learn Chinese surfing, cheap entertainment. I seriously recomend learning how to ride the bus without holding onto anything ^_^
KTV if you go varies on cost and time spent in KTV, a lot of chinese people drinking like a fish (or one irish american drinking a bunch of chinese people under the table) havent quite figured that night out. 300ish rmb for food and drinks for all
Mostly though let you girl know what your budget will be for when you arrive, before you arrive so she can plan things accordingly ^_^