I bought a top of the line Pfaff probably 15 years ago. I have never been sorry. The high end machines have features you just can't get on the cheaper stuff - needle down, dual feed, needle threader (only started using that recently), etc...
That being said, I still use my old faithful 401a when the Pfaff is in the shop. Even if there isn't a problem, the newer ones need to have maintenance work to keep them running well. I do all the maintenance on my old Singer and she has not spent a single day in the shop in the 30 years I have had her!