Well Bud,
You just recently opened your account and you have seven models. Research suggests you should have a minimum of around 30-50 models when you first open for business.
I have 31 models that I uploaded over the course of a year and a half and average two sales per month.
Some of my models have sold several times so it may seem like 5 dollars is low for a thing but if you sell it 10 time it is 50 bucks. since I started I've made a grand total of 120 bucks (1.5 yrs) and I think since I should have twice as many models up by now, that I'm actually doing pretty good.
Most of my models are low priced because that is what they are worth in this market. If I want to charge more I have to work harder making more complex and interesting or more useful models.
You can find hundreds of oil barrels and shipping containers for free.
You have to be patient because there are thousands of modelers here and on other sites to compete with that know their craft. It can be done with hard work and dedication.
I would suggest also spending time doing research. There are many tutorials on youtube on how to be successful selling models. I found it very useful to go through every page of every model category that interested me here on cgt to see what models are here, what the pricing, quality is like.
You find a model from someone with lots of models, lots of likes and lots of positive reviews. Look at the wire frames and texture sets etc.
