It takes 75¢ (if you use the same vial, 25¢ syringe/needle, 50¢ filter) and $1.75 (if you use a new vial).
So for an entire kit that’s adding $7,50 (or more if you use a new vial, $8.50 if you use one new vial for the entire kit, or max $17.50 if you use 10 new vials for the kit).
Any of the options from $7.50 to $17.50 greatly improve the safety (and over the long term, probably efficacy) of your $150 kit.
As far as time. You already reconstitute.
This takes 30 seconds or less.
Draw into 3ml syringe. Attach filter. Inject into vial.
Does that sound too “time consuming”?