Loveitloud,
I can also vouch for the Aragon 4004MKII being a low cost solution for your Stages. I use my 4004 to drive low efficiency (89db)planars and it drives them with ease and the combo sounds very good.
I agree with Jeffjazz, though, that mating it with a tubed pre is a good idea and a very good match (I use a VTL 2.5 with NOS Mullards) and this added the depth, texture and presence I was looking for. With a ss pre it sounds leaner and more sterile but has very good resolution and bass response regardless of the pre type.
Cwlondon said he left his Aragon on 24/7 for 8 years and it never missed a beat. Mine's been running 24/7 as well for the past 5 years with the same result.
As to your question on price, these amps are no longer made (was replaced by the 8008 model in '95 I think) but it listed new for about $1800 when it was built back in the 90's. I paid about half that 5 years ago so you should be able to get a nice one used for no more than $900. probably less. Its an older amp (1994?) but its built like the proverbial tank, is very durable and sounds more expensive.
OTOH, I think a Pass amp would improve the sound of almost any system but they are high priced. Sorry, I've never tried a Pass amp so I can't say if the extra $$ is worth it. Good luck.