Using the name brand product is the easiest.
You can find many less expensive substitutes. We see some as cheap as $5 on eBay. We have used them successfully when directly loading the HEX files.
Before buying a cheap board try to find out whether you will need a special driver on your PC. Make sure you get that driver or can get it if you need it.
If loading the HEX file on a cheap board gives you trouble as an alternative you can request, compile, and load the source software using the free Arduino IDE available free at https://www.arduino.cc/en/Main/Software. Use the downloadable version. Just copy the library folders included with the build package into the library folder of the IDE. Installing the IDE usually installs everything else you need including drivers for most boards.
See a range of options with this search on ‘compatible arduino uno r3‘.
