My only reservation with the condenser choices so far is that,
as mentioned, the Oktava's have quality control issues.
Other choices (under $100) would include the Studio Projects B1,
and the Marshall V67.
With the other $200 portion of the budget, here are some other ones
to try, and you can buy them used to save $$.
1) Shure SM57
2)
Electro-Voice 635a omni
3)
Electro-Voice RE15 (or RE16 which has an internal foam pop screen)
The last two listed above are easier to use for a singer who isn't
that experienced with proper mic technique BTW.
The Beyer M88 or Sennheiser 441, for example, can sound terrific
but they are hypercardiod (narrower pattern), and demand a higher
level of technique as a result. The positive aspect of this type will be
they'll reject ambient noise at home well.
As a generic vocal toolkit, IMHO, the SM57 and one of the EV's listed
here, along with a nice condenser, will work excellently for most singers.
Chris
P.S. If you don't have an outboard parametric EQ unit yet, it would be
a smart idea to take $100 or so out of the budget to get something
like a DBX 242, to have available during mixdowns.