Can you buy a product under your own affiliate link and then you will obviously get 75% or whatever back?? - so you don't end up paying as much. Just a thought...
Be your own best customer. So yes use your affiliate link to purchase if it ends up being an equal or better price.
You are welcome. Just make sure that the policies with any affiliate link does not state against buying for yourself (I am not aware of any that don't allow it) If you ever do adsense or the like, then it is a different product (advertising) with different policies - so then you wouldn't be a customer -because in that case it is stealing advertising dollars.