I didn't see your original post/question, but if you're referring to vaping the "juice" I would personally stay clear of that. Went and bought a Smok device got the juice and it did literally nothing.. But if you're referring to vaping flower, there are no parts to replace.
I've been using (and abusing) my solo 2 and it's still going strong. Just needs to be charged
There are cheaper electric versions, but I would not recommend anything from grenco science though. Do some research watch some YouTube videos. Sneaky Pete and the vape critics have some good info but they are a bit biast.
also check out the dynavap, if you're not scared of a torch /flame.. Pretty low initial outlay. And it hits the spot once you mastered the technique..
There are plenty online stores that's sell flower vapes. Vapestore, cock&bull, I can't remember the others off hand now.
You also get vaoes that can do concentrates as well as flower like the pax3 and one or two others.
Just Google dry herb vapes.
Hope that helps bud...