Looking good 🙂 Finally something I can reasonable offer advice on 😀
First. Increase your prices, some of the objects should have double the price it does now. I assure you that having low prices doesn’t help. Whichever studio or independent creator wants to buy a model, they’ll be looking at quality first, price second. And too low prices can raise red flags and make them think there must be something wrong that you’re hiding with these models if you’re selling them so cheap for seemingly no reason.
Second. Make more complex products. As nice as a simple table is, it’s just a table. Most people who buy something on turbosquid will buy something to save themselves time. Chances are, most people buying it will also be able to make a table or a plant pot in a reasonable amount of time themselves. (And yeah, I’ve done it before myself, lessons learned. Overly simplistic stuff doesn’t sell all that well.) Your furniture set, the mech or the desert lot are good examples of what you should be aiming for ideally. The more time you save for a person buying it, the higher your chance of a sale.
Third. I’m not too sure about this myself, but it might help you making more “generic” models. Your kitchen sink design is really nice. But also, it can probably only be used in one very specific sci-fi setting with a very specific art style. You might get lucky, and someone’s style will match yours and they’ll buy it. But you’d probably have better luck making something that would fit in more situations.
But besides that, the modelling and the texturing look great, there’s no glaring issues that I can find with the models themselves. Happy sales 🙂