How can I raise my bed frame cheaply?
Go get yourself an 8' untreated 4x4 (~$10.00).


Determine how much higher you'd like the bed to be, then cut the 4x4 in appropriate lengths adding an inch to each length.
For example:
If you want the bed to be 4&quot; higher, cut the 4x4 in 5&quot; lengths.

using a spade or Forstner bit of appropriate size (just slightly larger than the bed frames feet, so the feet will fit into the hole), bore a hole to the depth of one inch.


place the frame on the 4x4 pieces, such that the feet of the frame sit in the holes you bored.


NOTES:
Make sure you use untreated wood.  Pressure treated wood may damage, and/or stain your bed frame and flooring.
I'm assuming you have a drill press and the appropriate bits, so the cost of the project only includes the lumber.
Making the leg extensions too high could cause the bed to be unstable, leading to property damage, injury, and or death.