The cam isn't cheaper, its just not THAT MUCH more. With rockers you basically need to get stronger springs. So on top of that all you would need is a timing chain, tensioner, and sprockets, then the labor. There is nothing wrong with the stock pushrods and I would leave them stock unless you are looking to get really serious with the engine. A cam is the same price as the non-roller 1.9'*, and cheaper than roller 1.9'*, so the only difference is the timing chain/tensioner/gears, and gaskets. So you're basically looking at twice the power gain for $100-$200 more. Its all up to you to decide, but I think I would get the cam if I were you. If it were a boosted car then I would definately recommend rockers instead, however I just don't feel that you would be satisfied with the gain.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!