You could do it yourself and you would then incur only the registration costs which would be £110 for each document. If you follow the instructions carefully at the link I will give you at the end, you should be able to do this yourself, by downloading the forms, filling them in, signing them and attending to registration. I hope that helps. Please leave a positive rating so that I am credited for my time. Here is the link and you should follow each of the sections in order: https://www.gov.uk/power-of-attorney/overview
Yes you can and it doesn't cost any more.