When Borax dissolves in water, it produces the same boric acid that comes from boric acid directly.
Na2B4O7•10H2O ---> 2Na+ + 4B(OH)3 + 2OH- + 3H2O
Borax (sodium tetraborate decahydrate) ---> Sodium Ion + Boric Acid + Hydroxyl Ion + Water
after adding Muriatic Acid to compensate for pH you (pretty much) get the following result:
2Na+ + 4B(OH)3 + 2Cl- + 5H2O
Sodium Ion + Boric Acid + Chloride Ion + Water
It is true that by weight you need more borax, plus you have to also use muriatic acid, but that combination is usually somewhat cheaper than boric acid so the only issues are ones of weight and convenience (i.e. not having to balance to adjust for pH).
With the Borax + Acid approach, the only thing extra you end up with is salt. So get out of your mind any concern about the complexity of the initial Borax chemical as that is not relevant unless you are concerned with the 54% greater weight compared to boric acid and the extra acid you need to add when using borax. It's a cost/convenience tradeoff.