You wrote you would own a pair of Fjällräven trousers. So you are able to test them yourself.
I recommend you to wear them every day for every use.
Wash them in the evening if necessary and let them dry over night and put them on every morning.
They are made for that. It is expedition equipment, Trekking equipment.
Or better: They call it like this and tell the buyer it would last for years.
No experienced hiker takes a second pair of equal trousers with him. Experienced people use swimming shorts and rain trousers as spare clothing and additional merino wool layers.
So I recommend you to use your Fjällräven trousers how they should be constructed: I recommend you to wear them every day, 365 days a year. How you would do it on a world journey.
And than you can decide yourself, if you want to invest the money in the jacket!
My brother bought in the year 2017 the Fjällräven convertible trousers Karl, where you can zipp off the legs.
This trousers fell in pieces after one year of use. He bought two, by the way, in different colours, and both fell apart after one year of use. Round about 365 days of use.
I tested in the same time the trousers Steppe 300 from Decathlon.
After one year they didn't fall in pieces, but the zipper at the side leg pocket broke and the button broke after 3 month.
The Fjällräven trousers cost 150,-€, the Solognac Steppe 300 cost 16,-€.
Fjällräven produces in Asia, Decathlon produces this trousers in India.
So, the Fjällräven trousers cost nearly 10 times more than the Solognac Steppe 300, but they can be used both round about one year.
Perhaps you should wait with the investment in other Fjällräven products, until you tested well, wat you just bought from them.
Or you look for something else, made by a real quality producer.
Have a look at used Austrian Uniforms. They are olive green, made in Austria or Germany and very tough and cheap.
Or look for other real military stuff.
May be you want to invest larger amounts of money in real good other equipment like a Hilleberg Nallo 2 or Akto 1 person tent or a good knife, perhaps the Fjellkniven F1, or a titanium mug from toaks or Tomshoo with two types of handles, which you can hang over a fire, or a good Berghaus military ruck sack or the Snugpack Special Forces Sleeping bag System with it's bivvy bag, or Ullfrotte Woolpower 200 underwear with zipp color, or other quality stuff.
That costs a lot off money but it is worth it.
Clothing you can buy from the surplus shop next corner or new original field uniforms, who are usually better but cheaper than civil products!
That jacket here is very similar to the "Räven Jacket".
It costs NEW 30,-€ and is an original Austrian uniform jacket, made in Austria or Germany. (Several producers deliver it)
Polyester-Cotton mix 65% Cotton, 35% Polyester, really spark resistant, fast drying too.
That is a very good option in a multi layer system!
http://army-warehouse.com/10-servicecard-artikel/11-bh-kampfanzugbluse-kaz02-neu.html
