I have a fuzzy understanding that っぷる is something like っぽい (-ish) or っぷり (manner, style). Could you offer a more clear definition?
For example someone eating salad for dinner says:
貧乏っプルじゃないよ。ベジタブルっプルだよ。最近食べ過ぎで野菜をたくさん食べたくなるのよ。
I have a fuzzy understanding that っぷる is something like っぽい (-ish) or っぷり (manner, style). Could you offer a more clear definition?
For example someone eating salad for dinner says:
貧乏っプルじゃないよ。ベジタブルっプルだよ。最近食べ過ぎで野菜をたくさん食べたくなるのよ。
My guess is what you mean is the word ぶる ぶり (also ぷり) derived from ~振る ~振り. If so, here is some explanations...
The original word 振る is a verb meaning "act like". Examples are: 急に他人ぶる (act suddenly as if he/she is a stranger), 素人のくせに専門家ぶる (act as if he/she is an expert even though they have no idea). It is more often used to imply that the person isn't what they are trying to imply by their way of acting.
振り is more often used in a positive way, referring to the (honorable) way of acting. Example: 見事な食べっぷり (how he/she eats (in a grandiose way)), あっぱれな走りっぷり (his/her great way of running).
This further evolved into the slangy usage of ぶる、ぶり、ぷり. For example one might say 何貧乏ぶってんの?(笑) to mock a friend who made a lot of money by gamble or something and is wearing old shoes. Another example could be あいつの振られっぷりは毎回半端ない(笑)( he always gets turned down by girls in a grandiose way, haha). It's usually used for an humorous effect, so it's not a word you use often.
Your example sounds a bit weird and could be rewritten like this:
貧乏ぶってるんじゃないよ、ベジタリアンぶってるんだよ。最近食べ過ぎで野菜をたくさん食べたくなるのよ。
This sounds grammatically correct, but it still sounds weird/confusing because it's weird that you'll act like a vegetarian when you simply want to eat vegetables. A slightly better example would be:
A: またもやしかよ。何貧乏ぶってんだよ(笑)
B: 貧乏ぶってるんじゃないよ、ベジタリアンぶってるんだよ。ベジタリアンの方がもてるらしいから(笑)
EDIT:
This word has no relation with プル derived from カップル as in 馬鹿ップル. It's rare to use this ップル for anything else than 馬鹿ップル though. As a native I wouldn't recognize ベジタップル as a 馬鹿ップル variant.