Buy two of every PC ETB?

I'm new, and there is obviously a lot of recency bias, but could I theoretically buy two of every Pokémon Center ETB, rip one and hold the other for six months or so, then sell that to cover the cost of the first?

Maybe not fully cover but put a dent in? Essentially I'm trying to cover the cost of the hobby.

Is the PC ETB ever worth less than MSRP? What about a standard ETB? What would be the best way to sell one PC ETB every couple of months without having to go through EBay as I don't have an established account?