ESI is the way to go. MALDI would work also. Quadrupoles are great too.
Ideally you would want an ESI Quadrupole with an Ion Trap.
And they are really nice too, I use one pretty much every day!
Now, about cost and such....that is just research and finding the costs and some equivalent systems and comparing them.
The ESI Quadrupole with Ion Trap is really expensive though!