@placetime - any of those three would get the deed done. My only expierence with cheap glass was a 6 arm diffused downstem and it hit nice, but was extremely fragile and did break with a very light blow.
The first pic seems like a decent piece. The tree percs seem a bit high and i would imagine a water level above the slits would be close to the opening of the mouthpiece and one could get a lil drink.
The second is nice also, the whip attachment saves the need for another piece if its going to be used for vaping only. This reminds me some retailers (not sure if online sellers do this) give a discount without the bowl if you wont use it for combustion. I saved some on a recent purchase with this. The slits on the second piece are minimal and it doesnt seem the bottom is open so it could have some drag.
The third is quite interesting. I havent really seen a lil handheld bubbler with ground glass joints. The mouthpiece has some style to it, unlike some other cheap pieces. Looking at the pics on the site of the last one, theres a pic of the perc upclose. It seems some of the perc stems are not straight. Theres what seems to be a glass buildup at the top of the perc stems, which shows the method in which they were attached. It seems tree percs without this are fragile as it is, im not sure if this adds to their fragility.
On all 3, i noticed a glass buildup at the attachment points i havent seen on other pieces. On the first two, its right below the ground glass joint, where the top of the perc attaches to the inside of the dome. on high end pieces, they seem seemless, the blower must create these from one piece of glass, therefore no seems. This seems like quite the task with how elaborate percs are inside of other glass. Thats probably why they are expensive. On these pieces, It seems the percs are made seperately and attached with a glass connection. This could add one more fragile point to whats already fragile (glass)
i handle my glass pieces like babies. Always carried with two hands. Always carefully sat down. I will exclude my glass pieces from the session if any clumsy smokers are present. Extra special care during filling, emptying and cleaning cause thats when it happens a lot. If they are not being used, they are in a proper case. I recommend dime bags, as they got plenty of padding, lots of pockets for extras and i love the hemp style. They are soft cases, there are some hard ones out there for the ultimate protection.
I think any of them pieces will do you right and surely get the job done. Just use the same cautions you should do with any glass piece, handle it with care and it will do you fine and certainly last.
Im by no means a glass expert, just stating my observations, opinion and expierences. Hopefully can help.
-YGMP