Skid steer tires can be found in many places, but like everything else 'cheap' is a matter of opinion. Skid steer tires are available at specialty stores, as well as Amazon.com. Perhaps the cheapest would be available on ebay.com.
One can find more information about skid steer tires from the National 1 Tracks website. The website has information on solid versus pneumatic skid steer tires.
There are numerous tire brands that make skid steer tires. Just to name are few there are Titan, Goodyear, Bridgestone and many other tires companies.
If you do not know how to put on skid steer tires, I recommend that you take it to a professional or have someone who is knowledgeable help you out. It can be very dangerous to you or could ruin your equipment if you don't know what you're doing.
You can find tons of information on the BMW skid steer backhoe at www.skidsteerbackhoe.org.
You can find a great selection of skid steer loaders at www.bobcat.com
Steer in the direction of the skid. The idea is by reducing the friction the front tires have the sliding rear tires will come back into line.
You can find a used skid steer loader at www.equipmentlocator.com/elsm/skid-steers.htm. Another good website is www.skidsteerloaders.us
Skid steer tires are very good tires. They offer the force and protection that other tires simply can't provide. Although expensive, I would highly recommend them.
It does not matter the amount of hours that are on a used skid steer. If it is properly maintained and is in good condition then it is cheap.
Used Skid Steer Loaders are available online. The website http://www.equipmenttraderonline.com/ has thousands of listings for heavy equipment across the nation, including used skid steer loaders.
There is a Blog Spot blog page called Skid Steer Solutions which has a blog with an in depth review on some skid steer attachments. The review is thorough, but not overly long. You can also read one on a blog site called Skid Steer Attachments Blog.
Yes, you can find them at skidsteersolutions.com