I believe Borealis is 3D in size (a Mag85).
If you are really ok with 4D in size, you can make what I have for less than your budget:
1. quad bore 4D mag - about 90 dollars
2. borofloat lense - about 7 dollars
3. Fivemega bipin adapter - about 17 dollars
4. Fivemega reflector (with cam) -...