People keep saying that these Tools are expensive, but when you compare to other Tools they are not that bad. Some steam machines sell for 1000s of dollars, same for hot water extractors. So 400$ while it's not cheap is still a small investment.
Great thing about polishers is that half of the expense for using them is the combination of electrical extension, pads and liquids and those can be used on any model polisher you have so as I said, it ain't that bad.
My goal is to have 4 polishers, this will very likelly change when the new models start coming out after SEMA, but for now:
1 Flex 3401 with 5.5 inch pads for correction on very hard paint
1 Rupes Bigfoot 21es with 5.5 inch pads for most vehicles
1 Meguiar's G110V2RC with 3 inch pads for spot correction and small area correction (would buy a Griot 6 inch instead if I did not have the Meg already, learned it was twice the power for 20$ less too late)
1 Griot Garage 3" mini polisher for areas nothing else will fit in
Someone was talking about the fact everyone is coming out with large throw polishers after the succes Rupes had with the Bigfoot, so my dream would be to see a forced action with large throw this year... that would be awesome

Would probably use a 6.5 inch pad on that to speed up the process.