The difference in the price is probably that the $34 kit does not come with the pony emblem and the $54 kit does. I could be wrong, but double check what comes with the insert because I almost made that mistake when I ordered mine a few years back lol
I had one on my '92 LX and it was very easy to install. It's actually probably easier to install on a LX than a GT because there is a lot less cutting involved for an LX - it's basically already cut perfect for it. All that comes in the box is the actual insert and the emblem, so you have to have some urethane and some body kit screws to hold it in place. You basically just cut the crossbar thing where the Ford emblem is over the grille opening either side where it goes into the bumper cover. I then urethaned the bottom corners and pushed it in place. I then took some body kit screws and ran one down on each top corner (the top that the bottom of the hood butts up against) from the top of the insert down into the front bumper cover to keep it in place. I had it on there for about 6 years before I sold it so I assume it's still holding up.
It's pretty easy to install, the hardest part was figuring out how to start cutting the old grille out lol
Sorry, no install pics and I miraculously gained a Saleen lip kit, but it defintely looks a lot better with it!
Also, don't worry about the cuts looking that great, the insert covers up basically the entire grille area from turn signal to turn signal.