For years we ran those little N1 or whatever it was
that every studio in the world used.
Yamaha NS-10?
We use a pair of JR-149's. They are 1970's monitors in cylindrical
aluminium housings, designed by Jim Rogers after he left the Rogers
company (shades of Leo Fender...). Apart from the housings, which are
designed to reduce the out of phase internal reflections found in
square speakers, they are identical to the Rogers LS3/5a, the 'BBC
monitor'.
Why am I bothering to tell you all this? Because they are old and they
get mistaken for novelty speakers, they are really cheap. We got ours
from a car boot sale (flea market) but you can find plenty on eBay.
The only caveat I would add is to make sure you get a matching pair
with working drivers. Because the drivers are the same as as the
ultra-collectable LS3/5a and are no longer made, spare drivers go for
very high prices.
Cheers
Daniel