3G module similar to ESP8266

Anybody here who dares to create something like a small 3G module similar to ESP8266?
I think I do not need to introduce ESP8266 chip to you. In short, it is a small and powerful all-in-one WiFi chip. One can upload their own code to it, use several GPIO pins, it has low power consumption, and you can get it for under $4. This is ideal to start developing IoT appliances. But! Do you have WiFi signal everywhere? I don't.
So the next logical Google search would be for a cheap 3G module with similar abilities. You can find something like this for around $47. Wow, that is not a friendly deal.
On the other hand, you can buy an USB 3G modem in China for $10. It even has more stuff in it than I would need. I do not care about the plastic case and the USB/UART converter inside.
I would need a similar all-in-one chip with UART interface that would behave like a 3G modem. I would just connect a memory chip, external antenna, and a nano SIM card. The chip could have some more free GPIO ports which would support SPI and I2C. All for around $5-$8.
Am I asking too much? Isn't there anybody who would be able to design and develop anything like that? I am open to suggestions and wishing to support such a development!
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