The Ergo 2 and 10 cartridges from Aliexpress came out to $13.50 for me. The PepPens look nicer, but the pen by itself, on sale, would be $22 shipped.
Pen: $12.00
Cartridges (10): $1.50
Needles (100): $10.10
3ml Luer Lock Syringe (30): $7.10
Filter (10): $21
Not that bad all together. I was already looking at having to buy new syringes/needles as I don't have any and would have needed them in addition to the 3ml syringes I'll use during reconstitution. I would have had to buy 3ml sterile vials instead if I was using syringes rather than pen. Really came out pretty even price wise.