NPPL can save you money, but in my view only if you did it on Motor Gliders or Microlights and then if desired add the SSEA rating later.
I did mine on Motor Gliders. Cost was £60 per hour. Completed in about 45 hours. If I wish to add the SSEA rating, then as I understand things all I need to do is conversion training with an instructor (not even the need for an examiner). The instructor, once happy signs it up in my log book, and hey presto I can apply for the SSEA rating. No fixed min number of hours for conversion.
Whether this will dissapear under EASA I'm not sure.