the difference is £120 from single to both burrs, you need to decide if its worth while buying both if you are only going to change once in a while? but for a comparable hand grinder to do pour over you are in the 100-200 region anyways.
really depends on budget and what you want from it, you can do filter with the stock espresso burrs, it just wont be as good as what is with the filter set, but by no means bad, and what you never had you cant miss
Decent De1pro v1.45 - Niche Duo - Niche Zero - Decent is the best machine ever made -