The Sunday Market at Aiquile offers a wide array of products ranging from coca leaves to electronics. Some of the stuff you can get here is dirt cheap, others are more expensive. Nonetheless it's interesting to watch people and perhaps buy an item or two. I bought myself an interesting cloth piece used my the cholas (campesinas).
For those seeking a ride during the day, you're only option will be to get a ride in one of the many camiones leaving to Aiquile from outside Sucre. The price is dirt cheap, but not free. I actually road on a truck hauling big cement bags. It was the only option to do this route during the day. The scenery reminded me to that of Northern Mexico. It's a worthwhile experience!
Did someone said coca? Man, the locals where all over it in the coca stands. They chew the coca leaves to get the energy demanded by their jobs. This is a common thing in Andean region of South America. If you're headed to La Paz, check out the Coca Museum since it's really interesting.