I had this idea a few years ago. In theory, it seems easy, but there are a couple of hurdles. First off, is finding an injector. I came across one a few months ago in Florida who is willing to do extreme. Once you get past that, how to get it paid for is another obstacle. Donators want to make sure their money is going towards lip injections. This is a little tricky. The best way I could come up with is the donor pays the injector directly for the injections, and once enough was donated, injections would be performed. But that introduces other problems. For instance, donator could dispute the charge on their credit card. Another is injector may wish to remain anonymous.
Even if you find a work around for payments, there are still other things to consider. What product to use? Most fillers only last 3-4 months in full effect. After that, they slowly dissolve, lasting about 6 months. So to get the full stacking effect, you have to inject a lot of filler in first 3-4 months. Even at 2 syringes every 2 weeks, you top out the stacking effect at about 12-16cc. After that its just maintaining the look. The last few injections I did (2 syringes in November of last year) I finally was able to get Voluma. It is meant for cheeks only, but lasts up to 2 years (per Juvederm), but in theory, it appeared full effects lasted at least 6 months, I would guess maybe even up to 8 months. So you could possibly have a larger stacking effect. Also Voluma, is thick! (Thickest of all the fillers currently) It gives a great firm lip, its my choice of filler now. Its also cheaper in the long run. Voluma is $800 a syringe, but lasts twice as long as the next best filler. Juvederm Ultra XC Plus is $500. So 12 syringes of Voluma is $9,600 for 8 months, where Ultra is $12,000 for 8 months because Voluma lasts twice as long.
The it comes down to time. Everyone wants to see immediate results. Even if you have $10,000 to do lip injections, it will take a few months to get them all. Donators can get impatient, lose interest, or just have to spend the $$ on things in real life. Even those of us who get the injections are at the mercy of the injector. I want 6cc at once, but they just wont do it. I might be able to get 2-3 at one setting, but not what I want. We want it just as much as the donators do, if not more.
Its a hard thing to put together and to be able to keep it going. Especially since its such a niche market. You would have to get 100 donators to spend $200 each just for 1 years worth of injections. Thats a lot for a niche market.