fingerprint scanner module?

I'm going to develop a project based on Intel Edison that will need a fingerprint sensor. As this board is compatible with arduino I started looking for arduino's fingerprint scanners, but soon I realised that are expansive and in this field there isn't a lot of competition: there are adafruit and sparkfun products that costs respectively 50$ and 32$ and the cost in europe will be highter due to shipping and rate conversion. by looking for informations I understood that arduino needs an integrated system that does the whole elaboration because of the lack of memory and so it isn't possible to use usb fingerprint scanners or smaller modules... In my case the memory is not a problem, with 1Gbyte of RAM is possible to do almost anything. What I'm still looking for is if there is an Api/SDK that can be used easily with any fingerprint sensor on Linux as I found out that old notebooks and mobile phones like iphone 5s and samsung galaxy s5 use really low cost sensors (about 7€ each directly in europe) and would be fantastic to be able to use one of them. As alternative i saw that there are low cost usb readers but is possible to interface with them? maybe there are other solutions that I have not considered before, what would you suggest?