I'm certainly in prime alpaca territory. I am still getting my feet wet with them, and only have 3 for the last 7 months or so. That being said, here are some tidbits from my research and experience:

You don't *need* a barn for alpacas if you live where it is warm. You will need something like a tractor shed, carport, or some other kind of thing they can hide under.

You don't *need* to feed alpacas any fancy food whatsoever. We tend to think "prize animals need prize food" but all alpacas need is plain grass. Not even nutritional grass - just plain grass. It is what they are built to eat. The fiber stays thinner (read: better). Fat alpaca=fat fiber.

Alpacas should be sheared before it gets too hot. Fortunately where I live it doesn't get that bad really so they missed a year of shearing. I am shearing them soon though.

An alpaca ranch near me sold one (stud) last year for $114,000

OTOH I bought 3 boys (ungelded) for $900 ($300 each) from cattle farmers that thought they'd try them out. I think they thought they were boring.

The fiber is wonderful stuff. It really is. You can make a little money selling it if you can amass enough of them, but you are ultimately competing with South American imports - they have way way more.

In South America it is typically "Logan's Run" for alpacas. They get 7 years of life and are killed for meat. They also have a lot higher cria mortality rates. I have 2 teddy bears made from alpaca hide and they are LUXURIOUSLY soft. (but I can't let the dogs near em because they know they used to be animal skin)

Even bad alpaca fiber is better than most cashmere. This is undeniably true. Visit a farm and ask to touch (if the alpaca will let you) the oldest alpaca they have. It will be very soft.

Male alpacas will fight with one another, especially gelded. They have a linear ranking system. No chief and everyone else subordinates, more like #1 through N.

It is not the size of the alpaca in the fight. It is the size of the fight in the alpaca. This is true at the 60+ alpaca ranch down the road. There is a wee little guy that will boss around ANY of the other alpacas.

I've never heard of an alpaca spitting at anyone ever. People have been caught in cross-fires on rare occasion though. They are more gentle and timid than llamas by a long shot. They are faster than they look.

Crias are susceptible to being eaten by coyotes, wolves, wildcats, wild dogs. A llama, donkey or great pyrenees will do wonders. You can have a llama AND a great pyrenees but anyone will tell you donkeys and dogs don't mix.

Mountain lions and bears will go after adult alpacas. Then it is definitely good to have a llama AND a great pyrenees.

(back to the economy of them)

It IS a shell game of sorts. Some people are making great money off of the alpacas. The economy is probably not going to implode quite like ostrich or emu because there is an asthetic beauty to them that people will continue to value. The market will certainly fluctuate and I wouldn't go dumping money into it to turn it into a serious income personally. If I can make $1000 of profit a year off of them - I'll be more than happy.

They do need occasional worming medicine, nail trimming, and the males often need their battle teeth cut. I am going to have all of that done at the same time as well as shear them while they are drugged. Mine are decent sized males and won't just sit still and be sheared. They are too strong. They have to be bascially tied down. Calmer ones can be sheared in a squeeze chute.

They don't make much noise - unless they fight and then you'll get maybe upt ot 20 minutes of alien screaming. I don't think the sound carries that well but your neighbors will know. In the summer for me it has happened maybe 1 time every 2 weeks. No big deal.

Alpacas don't rip out the grass like horses do. Their poop doesn't stink and looks like rabbit pellets. Even fresh stuff is only stinky if you are standing in it and is still way less odiferous than any one of my dogs' piles. It is great fertilizer. They pick spots to pile their poop in. Mine picked basically a line extending down the middle of the pasture from the far fence to the barn. Right now it looks like I spilled a line of fertilizer down the middle.

In summation: If you want critters that don't need a lot of attention, eat but don't destroy grass (aka save you from mowing), can provide you with some very soft fiber, and are generally friendly they are great. Unless you are going to take a breeding program very seriously and show your alpacas all over the place, then just buy bargain basement alpacas and be happy with them. I've never heard of an alpaca that was un-manageable. NEVER TAKE A FREE LLAMA. There are lots of nice llamas, but there are also a fair number that are only really appropriate to use as natural mowers.

Best of luck!