[amideutch]

Barbee, the pictures were mine. Yote, the difference in the pots is what they are made of and how well they break down. The CowPots are the most expensive and are made from cow dung. So as they decompose they feed the plant. The only way to buy 4" CowPots is the 300 quantity count which is around $125.00. Smaller quantities are to expensive.
DotPots sold by Johnny's are made from wood fiber and the 4" x 4" pots are 50 each for $14.95. I used these and CowPots last year with good results.
The Jiffy Pots are made out of Peat Moss and wood pulp and the unit cost is 14 cents apiece. I've read that root penetration in peat/wood pulp is not that good and the pots do not readily decompose. I have no experience with Jiffy peat pots but I do use the Jiffy 7 peat pellets which I highly recommend for seed starting.
While I was researching the costs of the other pots I found there is another product on the market called FiberGrow pots that are made out of recycled paper and the 5" pots run $100.00 for 250.
So CowPots are the most expensive 40 cents apiece followed by FiberGrow pots at 25 cents apiece and Dot Pots at 30 cents apiece and Jiffy's at 15 cents a copy. So maybe the old adage that you get what you pay for is applicable here.
One word of note. Tomatoaddict has used CowPots also and said that Peppers she transplanted to CowPots did not do well but here tomatoes did fine. As I don't grow peppers I can't say. If you want to try peppers maybe try one or two plants to see if you get the same results as Terry.
These type of pots have lent themselves beautifully to the way I want to grow my tomato seedlings. Is this the best way for you to do it, maybe not. But other than sowing seed directly into the ground these pots provide the least amount of transplant shock to to your seedlings. With climate change going on and disease issues we had last year we need all the help we can get and a healthy plant is one way to assure a successful harvest. Ami