Using only 1 pump on a 4 pump doser & buying second hand

[onlytoby]

Hey guys!

At the moment I've only just gotten into dosing and have all for reef, so I will only need one doser pump. But, I have the option to buy a 4 pump koemer for £150 which is three years old.
Should I get the bigger doser in the event I dose more?
How long do they last? Is 3 years too close to the end of its life and just buy a single pump for cheap?

 

[blaxsun]

What size is your tank and how long have you had it? What are your water parameters and how stable have they been?

 

[Gtinnel]

For me it would depend upon how easy/expensive it would be to replace the heads and motors if they were wore out. If you can cheaply replace the mechanical parts then I'd probably go for it.
As for getting a 4 head doser and only needing one head, you will eventually find other things you'll want to dose and use more of the heads.