Why not go electric? No longer sold in Home Depot, but we love the EGO brand. You can get a pole saw, an extension pole, an edger (don't have), a string trimmer, a bristle brush (don't have), a hedge trimmer and a cultivator attachment (don't have).
Battery power is enough to get most jobs done. We have 3 or 4 batteries and 2 chargers, and we have never run out of battery power when trimming trees, bushes, etc. Great product. The only gas powered non-mower tool we have kept is our Husquarvna leaf blower/vacuum, and it requires a lot of maintenance and changing the carb parts to keep in running well, and that is with using the TrueFuel and other synthetic gas/oil mixes to avoid the issues associated with ethanol-containing gas sold at gas stations.
Just checked, and you can get the trimmer and edger as a package with the batter for $449 at Lowes. More expensive than the Echo model you linked, but we prefer the battery power and not having to run to get cans of gas/oil.