My only machine (so far!) is an Activa 220, with the usual attachments and a walking foot. Bought it from my local dealer when it was on sale. I have had it about 6 years and outside of general servicing, that is all it has needed outside of the standard cleaning.
I have found some of the presser feet of higher spec Berninas do work, but check before purchasing.
It is a good workhorse, however the throat space is so small I find it very difficult to free motion larger quilts.
When the Festival of Quilts is on in Birmingham (UK) later this year, I might just treat myself something a bit better. Hope the show has some deals going.
HettyB