The real answer is a good fork and spade and dig as deep as u can, forming a slightly elevaetd bed. Do not walk on the bed, use a digging/planting board. Total xost will be about that of the tines. You can dig a 4' x 25' [100 sf] bed in three hours or so in the worst of soils. Get the compost bed going and mulch the bed. Digging is purely mental and not all that physical. you will be more efficent in your gardening. I muct confess I had an 8 hp hourse for 20 years in fact had two at the end. Put new tines on both and a motor on one and sold them both.

I never found any tines that were very much better than the other. The custom heavy duty stress the pto transmission too much and it will fail over time. The fact is they eat dirt afor a living and wear out fast . I had a good sized garden and bought a new set each year. In 4 years I have dug 60 raised beds 4' x 30 ft each.

Look on ebay. The manufacturer is in Tennessee and I bought the hardened tines.

bolo tines do search on google good price around 112 to 120.00 This one ended but a lot to click on http://cgi.ebay.com/TROY-BILT-TILLER-REPLACEMENT-BOLO-TINES-/260656633062

I have had a Troy-Bilt Horse tiller for over 15 years, and the tines were rusted and worn. As I do with most purchases these days, I did a lot of research online. What I learned was that the best replacement tines out there are sold under the "KD" or "Key Dealer" name. At 6mm thick, KD Tiller Tines are up to 20% thicker than MTD's "original troy-bilt" tines (MTD, known for its mass market sales, bought the Troy-Bilt name and now makes Troy Bilt products).

KD tines are made specifically for Troy Bilt Tillers, and have the original two mounting holes. Some of the cheaper, "one-size-tries-to-fit-all" tines have three holes. Real Troy-Bilt tines only need two. I learned that the third hole drilled in these cheaper tines weakens the elbow, and can cause the tine to break. According to the paperwork that came with the set, KD tines are guaranteed for life against breakage .

I not sure where else they are sold, but I bought my set online from Clark Farm Supply (clarkfarmsupply.com). The full set (8 left and eight right) I bought was $119.95, and the shipping and handling was free. The set came with all the necessary hardware (new bolts, nuts and lock washers) and an easy to follow installation guide, which was a real time saver for me. It took me about an hour and a half.

Here is a link that might be useful: KD Replacement Tines for Troy-Bilt Tillers

Note: The pic here shows my Horse before I changed out the tines. You can see how worn they were.

K&D hard hat hardfaced tines 120.00 a set garenteed against breakage for the life of the tine get to bolo's for the absolute best digging experience