If you ever do want a SPARC for whatever reason, here's some info about them:
Sun hardware is very expensive. A new system from them is definitely not cheap, for example a Netra 5220 can be over $15k, and the Enterprise 5220 isn't much cheaper. Their multi-core (and high number of threads per core) Niagra chip-based servers also tend to stay above $8k, but I recall seeing a T1000 going for as low as $4k recently. All new.
But there are some excellent refurb deals for sun4u-architecture boxes from before 2005.
I'm not sure how much power you actually need out of a SPARC box, but over the last year my manager and I have bought at least 20 old boxes (fully loaded with HDDs, DVDs, extra NIC cards, etc.) from
Solar Systems.
Our last batch of seven Sun Fire v120s (1x UltraSPARC IIc 650MHz, 2GB RAM, 2x 36GB, additional quad-fast-ethernet PCI NIC card) came in at about $500 each, half of what their site says. I think our last two Sun Fire v240s (2x UltraSPARC IIIi 1.34GHz, 2x73GB, 8GB RAM) for something around $1,000 per system. Your prices may be higher than these, because we've bought more than a few systems from them over the past few months so we get discounts, but it shouldn't be too bad. You have to call them before they get you an actual quote, but with a bit of haggling you should usually end up decently lower than what their site gives you for "sample pricing".
For alternatives, we've also used
AnySystem, or any good Ebay storefront with large numbers of solid ratings will work. For extra hard drives for the servers, we tended to stick with
Global Micro.
So you can definitely get them fairly cheap as refurbished boxes, but don't expect anything fast or modern. The type of box you need depends on what will you be doing.
And stay away from any "Netra" servers. You're not a Telecom company, and you don't need NEBS-compliant hardware, nor the surcharge that NEBS-certified equipment tends to have. In Sun's case, any sun4u-architecture "Netra" server will have it's equivalent "Sun Fire" brand of server that has essentially the same hardware configuration (although some exceptions do apply, i.e. Netra 210 vs. Sun Fire 210). Also, I'd recommend avoiding any Sun Fire box that uses Fibre Channel drives. There's just simply too much work involved when swapping out FC drives for them to be worth it in a home/student environment. Stick with SCSI-based servers.
But if you want to actually find the individual parts and buy them, good luck. I've noticed that it's just easier and less time-consuming to buy the entire box, if the parts in question were built prior to 2004, give-or-take. Resellers' prices on parts can be outrageous sometimes, while the best way to get replacement parts from Sun themselves is to have a SunSolve account and/or Support Contract with them. Even then, the older the equipment, the lower the chance they'll have what you need. Probably won't get anything from them for hardware that's been EOL'd or EOSL'd.
In the end, the production volumes for SPARC parts and systems are small compared to the gigantic x86 market, so you'll find that things aren't very cheap or widely available.