--is merely a prescription vitamin combination, containing methylfolate, methylcobalamin (B12), and the P-5-P form of B6.

All of these can be purchased separately without prescription, so it all depends on what kind of drug insurance one has as to which way would be more cost effective.

There are two points that should be made--first, methylcobalamin is probably better taken/absorbed by itself, apart from any other vitamins/medications, as it is very easy to interfere with the absorption of the large cobalamin molecule.
Second, there is some controversy around the neurological toxicity of B6--there are some reported cases of B6 overdose, but as Mrs. D's B6 thread points out, this is rare and may be due to genetic mutation that blocks the conversion of B6 to its usable form, causing it to build up in the bloodstream; taking the P-5-P, which is readily usable/absorbable (already enzymatically converted) may bypass this difficulty.