It's common in China for the low-skilled labour in the factories that drive the country (and much of the global economy) to come from rural areas but a dramatic drop in labour supply this year is affecting all major brands of clothing and out of stock problems are becoming increasingly common. 

Each year after the Chinese New Year holiday, it's common for 10-15% of the unskilled workforce to not return to work at the factory. 
Generally they have earned enough in the previous year to survive in their rural areas and choose to stay at home.

This year has seen non-return rates spike as high as 30-40% leaving many factories dramatically short handed.  This labour shortage has already started impacting on supplies within Australia with Bloomfield Creations is encountering stock delays between weeks and months of a variety of commonly supplied products, particularly in the common sizes.  These stock problems are likely to continue into the foreseeable future.

Causes for the sudden drop in the labour market have been suggested as the recent increase in wages with workers from rural areas finding themselves with more money than in previous years making it easier to take a year off and also the increasing affluence of the Chinese making low skilled jobs less attractive.

Labour shortages and increases in the cost of materials will be affecting prices shortly as well offsetting recent gains due to the stronger Australian dollar.  If you order the same items regularly, it's safe to expect a small price increase in the coming months.