Nothing wrong with wooden ladders, but a good set of light trade aluminium ladders are better in many respects, ie, lighter (by a mile) longer lasting, more comfortable rungs, less maintenance.
I'm not sure about price, but a double extention ladder (aluminium) can be got for around the £100 mark.
You can pay a lot less to be sure (and a lot more!) but when you drop below the £100 mark you are going down to the D.I.Y stuff, and they are crap for daily use.
Although I no longer use ladders (WFP) I always bought really good quality light trade ladders, the 35ft triple is a bit of a beast, heavy and hard work, but still lighter than the equivalent wooden one. But then you want to be as safe as possible when you are 35 ft up in the air
Ian