Yes, the New Balance Mmt10 is still on the market. You can actually buy them through the new balance website for 104.00 and they have many color and size options.
You can get a pair of new balance mt10 shoes if you visit finishline, footlocker for men and women and you can also get a pair of those shoes if you visit JcPenney.
Yes, the New Balance Minimus MT10 is designed for long distance running (of over 5 miles at a time). Make sure to replace your running shoes every 500 miles or so to prevent injury.
Check online stores such as Zappos.com or Amazon.com they have a lot of different running and other shoes for less. If you cant find it at those try REI.com
Unfortunately, the New Balance MT10 shoes are not that inexpensive. My suggestion would be to keep checking on eBay if you don't mind a pre-owned pair. Otherwise, the best deal I could find online of $99.95 is at the following website: http://www.gearwest.com/new-balance-minimus-wt10-trail-womens-pr-9323284.html
In order to find the type of shoes which you are loking for I would suggest either checking online on the company's website or perhaps visiting a local store which specializes in running shoes and sport shoes.
Many options out there to hear what others have to say but check these out for a place to start. http://birthdayshoes.com/review-new-balance-minimus-trail-leather-mt10 is a nice option with a full review. Also check out http://www.runblogger.com/2012/05/new-balance-minimus-trail-zero-mt00.html for some great pics with complete review.