I highly recommend what the others have posted by going with an established local power equipment dealer where you can get sales and service.
I am on my second Echo string trimmer, the first was a manual feed head bought by my parents in the mid 70's to use on their property and it went with me when I built a house in 1991.
This trimmer was cantankerous from the beginning, hard to start and problems with string head but after a few modifications and several carb rebuilds I got over 20 years of heavy use out of it.
When I finally gave up on rebuilding the Echo around 1997 I picked up a new "Super Duper" Craftsman with an auto feed head "Oh Joy I Need That" mainly because I had a Sears card and was still strapped for funds from building the house. I will keep it short but it was the biggest piece of junk I had ever bought. Problems with the auto feed head after the first week, take it back to Sears and they have to send it off because they don't work on them, return time 2 weeks.
I get it back and still the same problem, bump the head and line feeds out all over the place, so I take it back and tell them it has the same problem and it hasn't been fixed.
3 Weeks and the weeds are still growing with no consideration for my frustration and my parents told me it would be nice if I came by their place with the weed eater things were getting a little bushy
Two weeks later Sears called and said my weed eater was ready to pick up "Oh Happy Joy" I really needed it!
I picked it up from Sears "out of gas" no way to test it out so I bought it home and put some fuel in it, after a few pumps and pulls it fire right up. I will say it had a good running motor on it, rev it up and hit the bump feed and string flew all over Hell and Half of North Carolina…POS!
I took it back to Sears and got a full refund with no argument, this was in the days before they became Sears/Mart…YMMV Now.
That day I went and picked up an Echo SRM2400 from an established local power equipment dealer, I think it cost around $269.00 then (1997), they asked me to bring it back in after one month of use for a free check up and adjustments. It hasn't missed a lick since then.
I have added a Stihl FC-85 stick edger, RedMax EB7001 back pack blower and a RedMax LRTZ2401 long reach hedge trimmer to my arsenal of equipment, all have performed flawless.
Pay a little more to an established power equipment dealer with quality products and service and it will cost you less in the end, in many ways.
Later
Kelly