In a ideal world ,bought seed potatoes would be 100% healthy, disease free, undamaged, well stored and true to type. However, it is dependant on selection,storage,handling, integrity and freedom from human error.
Regarding your saved potatoes, if you can identify and exclude defective tubers, knowing that all your crop has survived since harvest without any problems, and that each used potato was sound when cut through,that your competance is equal to the average grower, then you are in a sound position to utilise the ‘survivors’ as ‘seed’
Unfortunately ,in my experience, paying in the region of £4 per 2 Kg does not enhance the certainty of success.
