I have a B-Vario and single dose with it exclusively. It does a great job at it and I believe that not only would it be a great choice at your price point, but most likely the best choice.
See massive testimonial here:
The Baratza Vario Grinder Owner's Thread. (Coffeegeek)
Its a lot to read, but to give you some cliff notes:
- Terrific customer support directly from Baratza
- High percentage of satisfaction amongst large variety of owners
- Vario has been
"de-bugged" and nearly all current Varios for sale are
updated*
The grinder has been described as yielding the quality of the legendary Mazzer Super Jolly but having a kitchen friendly footprint. It interchanges between press pot and espresso in a split second and has enough precision to adjust quite well to any coffee. An available timed dosing feature makes repeatability a snap.
But to cut straight to the point for YOU, the OP, the grinder has minimal grounds retention which will be great when you want to single dose and switch beans. If you were to go with a Super Jolly, the grind chamber will hold more coffee, the chute will need to be swept after every dose, and perhaps even a simple doser vane mod may be in order to help keep the doser tidy. For the Vario, you may run a couple grams of coffee through it at the beginning of session to ensure previous grounds are discharged and you are only getting the desired blend/SO. I would say that you would probably want to do this with a doser as well, it's just that the Vario doesn't require all the other work and will simply dispense your pre-measured coffee into the PF basket.
Thats not to say a doser style grinder wouldn't suit you, they certainly have their upsides. I'm just not a doser-type guy so I'll leave that up to other members who can paint a better picture.
Cheers,
Jackson
*The only revision you may have to search for is the updated board. The new board has a sleep function and will store your time settings for dosing. Personally I find it quite trivial and it costs an extra $20.00. Units with the old board are ~$429 and units with the new board ~$450.