I used to believe in your guy's method of getting some cheap good sound...
until i realized that without a muffler on your exhaust system, you basically lose a $hitload of low-end torque. This kills your every day city driving. Sure it will benefit your high-end, but how often are you at WOT flying around town? If so, you're probably wasting gas when you originally cut off the muffler to gain performance and mileage.
Not only that, but i used to work on 5.2L jeep grand cherokee engines. We had several cases where snot-nosed little kids ruined mommy and daddy's 30k dollar SUV's by using cut-outs and running without mufflers. Cutouts (although an awesome way to switch from open exhaust to closed) can let in cold air through the exhaust straight back into the manifold, cracking heads and causing damage.
Because of all these reasons, i feel that spending 100+ on a muffler is well worth it. Considering the fact that it costs at LEAST 50 bucks to get your muffler cut off, a straight pipe welded on, or have the resonator cut off and run a dump.
If our ram's were meant to run without an exhaust, they would've come stock at least with some type of open exhaust. Mufflers dont only reduce sound and noise, they give the engine enough backpressure to perform efficiently.
My .02