I have been using a 135 ft inverted-L for about a year made using the kind of wire sold for "invisible" buried dog fences. It is 20 ga. solid copper covered in a UV resistant tough HDPE insulation material. The wire is light, durable and when thrown over tree branches it is self supporting and insulated. It is so small in diameter and since HDPE has low coefficient of friction, ice and snow don't seem to stick to it.
I knotted the wire itself and tied a nylon cord and counterweight to the far end. Three trees support my antenna and the longest unsupported leg is about 60 ft + about 15 ft of nylon cord to reach the far tree.
End fed against a city water pipe ground from my basement with MFJ 941C tuner allows me to use it as 1/4 wave on 160, 1/2 wave on 80 and full wave on 40M. It also works well on 20m (30m works well, tuning is touchier). The copper water pipe ground is several feet from my station, and I believe the antenna works well, in part, due to this grounding connection.
The antenna works pretty well with my Ten Tec Tkit QRP rigs on 80m, 40m,30m and 20m. I have found it does better than my 1/4 wave coax fed marconi / vertical antennas on all bands roughly 80% of the time.
I bought 500 ft spools of this for about $25, so material cost is ~ 5 cents per foot. Total price of the antenna (w/o tuner) is $6.75. Feedline is the antenna itself. Entry through basement window involved adding a strip of vinyl electrical tape at possible wear points, however no wear is apparent.
Almost forgot to mention, due to small diameter it is very difficult to see once up in the air. I live in an antenna restricted community but nobody has complained about my "inverted dog fence" antenna.
73, NG9D