There must be dozens if not hundreds of ways to do that. If I needed many cheap ones and only 2G I might get a bunch of Mikrotik mAP lites. They are tiny, have a magnet to conveniently place them and are $25 USD/each: https://mikrotik.com/product/RBmAPL-2nD
The internet is full of tutorials and forums to help configure them.
If you describe the application in a bit more detail you might get some more specific recommendations. What type of devices, how many, how reliable do they need to be, what frequencies preferred or needed, etc.?
Best.
- Ex community all-star (⌐⊙_⊙)