Patriotic Chinese as well as foreign military gear collectors are increasingly being serviced by Chinese entrepreneurs who are taking advantage of the fact that most Chinese army military equipment (except weapons and some electronics) is also available on the civilian market. Once these entrepreneurs saw how eager Chinese were to buy army uniforms, field rations (like U.S. MREs), patches and all sorts of odd bits of equipment they began offering the stuff on eBay for the international market. There they found more collectors (or just curious eBay shoppers) than they anticipated. Chinese manufacturers have increased production of some items just to deal with this new civilian market.
The Chinese military does not, as in most communist police states, get all their military gear from state owned and operated firms. No, as part of the economic liberalization implemented in the late 1970s the military was encouraged to get the most (and best) for their money by soliciting items from multiple, mostly privately owned and highly competitive companies. Chinese and foreign collectors are seen as another market and that market is being serviced.
China began modernizing its army in the 1980s, an effort that was long overdue. By the end of the 1980s China had (at least on paper) motorized all of its infantry divisions. Before that, many infantry marched, or took the railroad, while some of their heavy equipment was still moved by horses. In effect, in the early 1980s most Chinese infantry units were equipped like Western infantry were in the 1930s. By the 1990s more infantry division were getting armored vehicles and by 2012 many infantry units were getting a third generation of armored vehicles, or IFVs (Infantry Fighting Vehicles). This makes them mech (mechanized) infantry. All the vehicles were Chinese made, and often Chinese designed. So was all the other new gear.
The army modernization included new uniforms and combat gear, including new assault rifles. The military PR people made sure all this new stuff got plenty of coverage in the media. It was quickly discovered that all this new gear was very popular with most Chinese, who had seen their military regarded by foreigners and Chinese alike as antiquated since the 19th century. Now Chinese troops looked as spiffy and menacing as their Western counterparts. The Chinese were proud and having some of the these modern military items around became fashionable and popular.