Truck : 1992 GMC Sonoma, 2.8 v6.
Problem: Sometimes when I goto start my truck I can't turn the ignition and I have to wiggle it around and try pressing in a bit or not pressing, basically its just finiky.

Any help? How hard/costly is it to get a new ignition. I know I'll have to get new keys and such, just wondering on how hard it would be to do myself, or how much from a mechanic.