Espressif shared the news about a the new version of ESP32 called ESP32 PICO D4 a few weeks ago. The ESP32 PICO D4 contains 4MB FLASH memory .

Now, here is developent board which contains ESP32 PICO D4 [datasheet]. You can buy it on aliexpress for 8.50 USD + shipping (in my case 1.81 USD).
The board contains ESP32 PICO D4, USB-UART converter, battery input for Li-Ion, internal antena and u.Fl connector for external antenna
There are two 2x10 pin header where are connected pins from ESP32.

The price of this development board with ESP32 PICO D4 is 8.50 USD and the shipping (in my case) is 1.81 USD.

Link to aliexpress store: https://www.aliexpress.com/item/TTGO-T7-ESP32-Module-PICO-D4-4MB-SPI-Flash/32841601867.html