Depends, though something better would be to wait and save your money. You can get a lot of bang for your buck above $125.
even a crappy bong will offer some diffusion, and you will be able to take a bigger hit than a pipe...it just wont be as smooth as with a nicer bong, and the glass quality will probably be bad, so it may break easily. Even so, if you want that filtration the bong will work. Even if you get a $50 pipe, it probably wont hit better than just about any less expensive ones, it will just look nicer, and probably be better glass. Personally, I would save up a little more and get something a HVY beaker, or if you really want to stay at $50 or so, you can get a nautilus for $55, which would probably be the best hit you can get in that range, but its known to be fragile.
No, it depends on what you want. A shitty bong will diffuse better, a nice pipe will look very nice, and a decent bong (although a bit more expensive) will probably give you a smooth hit and also a durable, long lasting piece.
http://www.grasscity.com/int_en/percolator-bong-blue-black-leaf-1.html 50 4.2 glass tree perc ac a little smoother a little more draggy or clears fast hits hard 3.5 glass straight tube 36 http://www.grasscity.com/int_en/weed-star-tx-burner-2-0.html or some shitty swirly color's that will get dirty and will be a harsh ass hit
Its definitely an opinion thing, if you want glass for art then yeah, the pipe would be much better. If you just want diffusion and a good smooth hit then a tube will be better. Also a good bubbler would be an option.
tbh, when I first started smoking and getting a tolerance, I had a hard time getting high enough after a while when I only had a spoon. My throat gets too harsh and its just uncomfortable. then I got a bong, wow. I think the highs are different, because I love that feeling after a huge rip, and your head kinda goes, "whoosh", and you just chill and forget that you didnt take a second rip. Thats just something that doesnt happen to me with spoons, and most dry pipes because I am a little more conservative with my hits otherwise.
a bong that is only $50 won't be very good. I'd do the pipe/bubbler route for that amount. I spent $58.30 on my bubbler, i'd spend at least $80 on a bong.