Bicycle Mechanics - is it really just my shifters?

ive been having trouble with shifting gears. i fiddled with my rear derailleur for bout an hour and my gears are faaaaiiiirrrlllyyy smooth/er, i cant get the fine tuning down, but with my front derailleur i have to almost hold my shifter forcfully past high as im going hard in my smallest rear cog in order to get to my biggest front cog....people are telling me its just my crappy shifters (shimano revoshift gripshifters that came with my bike) is that it or does my front derailleur just need adjustment and ppl just be hatin on the grip shifters? ive been looking at the price of shifters and man theyre not cheap...
edit: more than half of my shifter space is used for my smallest front cog, the few ticks left on the shifter go to the middle cog, and like 1 or 2 ticks left (including h) go into trying to get into biggest cog....
ill post pics after work if what i said is too much garble...

The first thing to try with any shifting problem is to check that your cables are moving freely. In this case it sounds very much like that could be your problem. One more thing to check is that the limit screw for the front is properly set. If it's too far in that would make shifting to the big ring difficult, but not just under load.
However, there could be an element of shifting technique coming into play. From what I can read of your post, it sounds like you're trying to shift the front under full pedaling load. This is the worst case for shifting. Try easing up slightly as you make the shift, it should help a lot.
While your shifters are lower end, I believe that you will be able to get good performance from them. Look at your cable condition, adjustment and technique before spending on upgrades.

Shifters aren't cheap?? Depends what you can cheap. I have used the 7 speed tourney trigger shifters (SL-TX30) from Niagara for several rehabs, they cost $12.73. And for that price, they come complete with all SIS housings and cables. To me, that's pretty cheap.

As far as adjusting what you have, go to the park tool site. They have an excellent tutorial on derailleur adjustment.

+1 Before you replace anything, I would look at technique, cable condition, etc.

Quick check for stretched cables... Shift onto the smallest cog and check for slack in the cable. See if you can pull it away from the frame at all. There should be essentially no slack, but it shouldn't feel overly tight either.
Most Shimano shifters, even the cheapies, are sort of a toggle switch. They either work perfectly or not at all.

i was on parktool and it says the front part(most outer peice) of the derailleur shouldnt be higher than a few millimeters off the biggest cog and my derailleur is prolly about 4 pennies(lol best i can do to vision it) worth higher than my biggest cog, i also noticed (tho i havent tried the gearing down to smallest cog bit) that my cable when on big cog is quite tight