Nothing cost wise compared the until recent market rate of $10K for honorariums to the licensing officers, and a lot easier for the average person that becoming famous or making friends in high places. As long as it is left to the private sector things could work.
What I do see if it becomes shall issue and training used as an obstacle is onerous requirements. The system came in kicking and screaming against the armed pilot program. Instead of going to a local range for private sector training and qualification, they made it a mult-day course in (I think) New Mexico to make it as inconvenient as possible to keep the numbers down. And on top of that, had to designate these pilots as "federal officers" to avoid the spectre of armed civilians (using the Webster's dictionary definition of that term).
Then there is storage - perhaps a requirement for a TRTL60x6 safe or similar.
If NYC becomes shall-issue expect no increase in the licensing department, continuation of the $1000ish fee, and a multi-year wait for an appointment. The licensing unit may never even grow big enough to handle the constant influx of people moving it or becoming of legal age ... and it will switch from needing a connection to get approved to needing a connection to get an appointment. NYC will not easily fold.
When there was a proposal to unrestrict all target/home only permits in NYC under the Koch administration the announced contingency plan if it passed was immediate revocation of all restricted NYC pistol permits.