It's hardly surprising to see Blade Splicer recovering from reprints. She saw lots of play during her time in Standard, especially in Birthing Pod decks. Blade Splicer would slide into Birthing Pod Modern decks, as well.
Does Blade Splicer Still See Play in Modern?
Even with the banning of Birthing Pod in Modern, Blade Splicer still sees top table Modern deck play in Eldrazi and Taxes and Hatebear decks. These decks really like Blade Splicer because of all of the "blink" effects in the deck. Eldrazi Displacer, Flickerwisp, and Restoration Angel can allow to reuse Blade Splicer's enter the battlefield ability again and again. She also does fairly well in EDH.
A card with the competitive pedigree of Blade Splicer couldn't stay around $1 forever. Even the New Phyrexia foils held at $3 and MM2017 foils at around $2. The low Blade Splicer foil price is due to being a foil promo in an intro pack deck. But, even that extra supply won't last forever.
Why is Blade Splicer Good?
Since Blade Splicer gives any Golems you control first strike, it's possible a golem creature might be printed at some point that will work well alongside her. We have seen her and Solemn Simulacrum work well together before. First strike is a very relevant ability. Four power for 3 mana is also just always going to be good.
While it's not likely that Blade Splicer will skyrocket in price, she will not remain cheap forever. It's always good to catch these long-term MTG card stocks to hold early. This is a card that can only get better with time. Players aren't really going to let her go at this point. Of course, Blade Splicer foils are the better investment, as they will be considerably more valuable sooner.