If you want to buy a dirt bike and you are under limited budget, I would prefer you to work somewhere for some time and go for better quality dirt bike. If you keen on buying dirt bike and not looking for frequent troubles form them, then low quality bikes are not a preferred option. Cheap dirt bikes are false saving unless you just want a dirt bike for a simple leisure ride. Here are some reasons to prove that cheap dirt bikes would be a false saving.
Cheap bikes being made from cheap materials need regular replacements. This would become absolutely expensive for you. The cheap materials used to make the bikes like cheap plastics, soft metals used in the body would create regular troubles for you. Battery issues, clutch cables problems, chain sprockets being worn out, handle bends, bearing damages, lever issues are some of the most common issues with cheap dirt bikes. The cost of replacing all these parts individually would be one of the main things that you would have analyzed by now.
Regular maintence and service
If you consider that rate of inspection you need to do while using cheap dirt bike, I would say, every time you take your bike. The screws and bolts used in the bike become loose often. The tires are to be maintained frequently for their poor quality. Also, poor quality engine of the bike needs regular servicing and may consume more fuel after a period of time. So again these are cost adding factors and prove expensive within short period.
No resale value
When you buy cheap dirt bikes or pit bikes you may be spending less. But in case you want to sell your bike to upgrade or for any reasons, there is very less resale value you would get with cheap dirt bikes. Considering all the dirt bikes, used Chinese dirt bikes are not sold anywhere. So again, not cost effective when you resell your dirt bike.
So, even if delayed it always better to go for quality. Being said that you also need to consider your requirements and the way you are going to use the bike.