i am not a pharmacist but i did work for two years in a pharmacy owned an run by my husband and his brother (none of them a doctor or pharmacist either).
pharmacies operate without the pharmacist very easily. the workers are often not very smart (i worked with a woman who could not write a sentence without at least few mistakes). all they need to do is read what the prescription says, find it on a shelf and then charge for it. also, 90% of dominicans know what they want (amosisilina

). there is very little room for advice and it would be mostly things like headache, toothache and gripe. really, only a rudimentary knowledge is needed to be able to do that. after one year in the pharmacy i was on a par with our best worker who had 16 years of experience (not an educated pharmacist either), all because i opened every single box we had to read what the medicine was for, how to take it and so on. i also read an encyclopedia of medicine whenever i was bored. and btw, when i started working my spanish would go no further than some basics!
what real pharmacists do? someone who has enough money to properly study for this title has enough money to start his own business. or maybe comes from a family that has a farmacia. or maybe goes to work for one of the pharmaceutical companies in DR (this business is booming, btw).
farmacias for sale... you would mainly need to look and listen. there are few pharmacies currently on sale in POP but really, you'd need a dominican middle man to go about this business. i suggest a good lawyer who'd be able to check all the paperwork and negotiate a decent price.
the price of a pharmacy depends on many things. building (owned, rented, size, possibility of physical expansion), location (obviously), inventory (the bigger the pharmacy the more stock it has). the last factor that is worth money as well is, of course what is called here a "punto" (lit. point): that is an intangible value of the business. not sure how all this is called in english. but for a ready to run farmacia in POP, in a good location, with everything included, you'd have to part with 250k dollars (american), maybe. maybe more, maybe less, depends of farmacia and your negotiating skills. you could of course buy something small cheaper and then slowly invest to build it up. but pharmacy business is not cheap. i would not be surprised if an owner asks a lot more that 250k.
ensuring the paperwork can be left in the hands of a lawyer. if you have a good one he/she will be alble to check all the permits and documents.
making own medications is virtually unknown of, at least in POP. i know that salud publica (government agency) does it, i know, in their dermatologia department. but i think this starts to pick up slowly again. and yes, that is actually a job that can only be done by a licensed pharmacist (dominican licensed, btw, as an american you can legalize your papers here, i think).
how do the doctors work without the aid of a pharmacist? simple, they do not care! the prescription says xyz, you sell xyz, that's all. doctor is god!

frankly i normally just give out the medicine as prescribed. only sometimes i would say: this cannot be given together, this cannot be given to a child or a pregnant woman, this is too strong/too weak. i politely explain that xyz is not recommended for indicated use and the doctor should be consulted again, just in case. this advice was, actually, always well received and many people came back to talk to the gringa because "gringa sabe" (gringa knows)

i have to say that i do not like to act against the decision of a doctor, who should know better after years in a medical school but sometimes i have the pangs of doubt...
i am not 100% sure with the body responsible for permits for pharmacies. i know it will be salud publico and DNCD but there may be some other entities involved.
Ministerio de Salud P?blica y Asistencia Social
http://www.dncd.mil.do/