I think the price dropping is a simple market adjustment. The morph isn't difficult to produce, being a co-dominant or dominant trait, and the pricing early on was being artificially controlled. Now, in regards to investment vs. personal preference:
The spider isn't my favorite morph. In fact, I like several morphs better. However, they are a striking morph, being very easily distinguished from a normal, and I believe the demand is there, and will stay there. First, on their own merits, they'll be desirable, second, they'll be desired as a component in many designer morphs. My real personal preference is for a bumblebee. =) The spider and any female pastels I produce will be toward that end. So, my pastel project and my projected spider project are both to found my bumblebee project.
I'm not too concerned with the pricing of the spider for a couple reasons. First, let's say that I pick up a male for today's prices of around $10k. (I've seen them from $8k to 12k recently, so I'm just picking a number in between.) Now, let's say that male spiders drop to 5k in 2006. My boy still isn't ready to go yet. Let's say when he does breed, in 2007, prices have taken another steep adjustment to $2500. Then I bomb, and don't produce anything. Incubator overheats or something. Next season, people are all buying something else, and spiders are now going for less than low end pastels are. Anyone can pick up a male for $500! I'm screwed, right? I spent $5k and now any schmoe can get the same thing for a tenth of the price! I lost 90% of my "investment." Ok, so now it'll take ten spider babies for the male to pay for himself, to "break even" (let's say 11 or 12 if you include expenses for maintaining him all this time). Ok, I get lucky, I get a dozen spiders when he produces in his third season. I sell them all for $500 and wholesale the normal males. By this time, I've gotten my money out of him. It's taken three years, but the little guy has paid for himself. If he keeps cranking out $500 babies, I'm still making money off of him.
Now, that's assuming he's not breeding female lemon pastels and producing lemons, spiders and sometimes bumblebees. It's also assuming an absurd final price drop. I wouldn't expect spiders to bottom out at $500 any time in the next three or four years. Besides, looking at him as a business and not an investment, he's not too bad a choice. Investment implies that you put some money away and it gains value for you, frequently folks into herps assume a short timeframe, which is bad investing anyway. Business implies that you take your inputs (pythons, time, rodents) and ADD value to them. Every snake he produces has some value, and as long as he's reproductively sound, he'll be cranking out snakes that can contribute to the bottom line. Spiders will remain a key ingredient in future designer morphs, so they'll always be in demand.
I think spiders and lemons are going to be two choice snakes for newer breeders to acquire. Since the bp morph market is a breeder's market, and the only way for such a market to grow is to bring in new breeders, these snakes will both continue to be in demand, and will probably not bottom out below about $1k. The same goes for albinos and ghosts at the moment. It looks like pieds are getting there. Actually, I'd put pastels, ghosts, and albinos on the bottom price rung, which makes them the entry level snakes of choice, followed by pieds and spiders, which are slightly more intermediate, but still within entry level prices for a lot of people. The newer morphs are always going to go around the more established breeders for a while at inflated prices (or seemingly inflated) until supply approaches demand and second teir breeders, the guys with impressive collections who still aren't the "big guys" yet, start producing them in enough numbers for the intermediate and beginning breeders to get them affordably.
What morph you get depends entirely on your business plan, I think. If you want to get in on high dollar morphs early and turn around a faster profit, then that's a viable approach. The main drawbacks are that you can possibly be caught off guard when the market makes a large price adjustment, and that you will have a much smaller market to sell to. You could also go the route of producing for the intermediate and starter breeder market, where there are a lot more buyers available, and simply produce more snakes. Or, you could go straight for the beginner/pet market and produce even larger quantities of snakes to wholesale.
I'm starting off going for the beginner/pet level of market. By pet I don't mean normals, as you'll get killed by imports, but simply lower end morphs that more serious hobbiests will drop some extra money on just to have, but may not have much ambitions to breed as a business. The guys who just want a morph so they produce some animals to trade/sell to get the next morph, and so on, but are doing it more for the sake of hobby than business. I plan to move up to the more intermediate marketplace and participate at that level myseslf at some point, though. Since I don't really like albinos much, I'm initially focusing on pastels and spiders so that I can raise funds for pied groups and so I can produce bumblebees. My reasoning is that you'll move the lower to mid priced morphs much faster since there are a lot more people with $1500 in their pocket than $15,000.
Of course, now you've got me worried about the possibility of genetic defects in the spiders, so I'm off to do more research. Any links would be appreciated.