The REO is probably the best Bottom fed device on the market right now (for its price)
You can get a REO for 115 bucks in REO's scratch n dent section. (rarely a visible scratch or dent)
Otherwise, you can get a cheap 115 reo mini. they take 14500 batteries, so you'd need like 4 batteries.
I love the 14500 and I cant wait to get a regular sized REO. These mods make life easy. Trust me.
Then you have other bottom fed mods. Theres the nice wooden one that was posted above.
I find that most of the mods that can come close to REO on quality, are usually around the same price.
So I'd go with a reo over a wooden mod that works like a reo, but thats just me.
If you already have tube mods that you drip with, then you can sort-of turn those tube mods into Bottomfeeds.
You can get the smoktech diver, which is a rebuildable atomizer inside of a tank. (pretty cool check it out)
Or you can just get into the clearomizers, like the BCC clearos. (bottomcoilclearo) Like Kanger T3 or evod or protank.
My best advice to you, is if you have some money to spend on something that will make vaping much easier...
While also being a good investment (resale value typically is same as new) The REO mod is what you need to research!