Let's talk some numbers...
With imp fap you can do imp fap service.
You can do in average 6-7 hrs of fap/day with 60ped/hr. The decay is in average 10-12 ped/hr, and on some occasions you do get some tips.
Consider you make this for 5 days a week, 52 weeks/year, that is 260 days.
That is 7*260=1820 hrs.
That is 109200 ped/year you can get from other players from your fap service alone, not including tips. Decay will be like 2-3k ped maybe. So is over 100k ped/ year proffit, making some skills and paying for the fap.
Ofc, those numbers are there only in case you are uber lazy and you don't want to fap too much, because you can have 20-30% more out of that.
I would say that in 2 years of fapping you have over 200k ped and one imp fap for free... And some paramedic skills. Not that many, because of the lower decay, but you would be surprised how much skill one can make out of fap service...
For a hunter, it is a huge advantage to have an imp fap, because it is the most imbalanced item in game, except for mod, ofc. It expands your level to something you could not do without such an item. You have acces to mobs you would not touch in any other way. Except paying a fapper, but that, again, will outline the value of the fap.
The difference from a fap and a land is that with the fap, you will work for the money, but with the land, you can wait for money to come to you and do nothing. Huge advantage for fap....
Then again, how many lands can make 10k$ proffit/year? Not counting proteron/TI/NEA and lands that are clear more expensive than a fap...
In reality, most lands that make any kind of proffit will need you to put a lot of effort in promoting them, spend money in events, time in checking screens or contacting people, or doing other type of work. Maybe easier, but you get no skills and also you may not even get the same profit in a year as with an imp fap.
For those reasons, I think that anyone selling for 150k is a very desperate man. Because is clear that the item is worth for real 200k ped, but because of the lack of ped on the market it will go for around 180k or so. But IMO 180k is already low.
You can not compare the imp fap with the other items in game, simply because it is so imbalanced. It is a game changer. The advantage you get by having the imp fap is so huge, that none of the people who have it are willing to let it go cheap. Because they know what those numbers mean from experience.
When using the fap you see its real power. Who never had such a fap will see it just like an different fap, a little better and more eco. But this fap has way more advantages than just the fact that is eco. For a hunter, it would be gold even if it would be 25 pec/click instead of 2.
So, in my opinion, if you sell for lower than 180k you make a big mistake.
Prices may/will go down, but the fap has a good reason for that price tag. Do not forget it. All other items that lost the value had valid reasons to lose that value. Like limited weapon competition, UL stronger items, XT at 120%, martial (L) almost TT food and so on. That makes all weapons and armors lose a lot of value. L faps are no competition for imp fap even when the user of L fap is level 100+ paramedic. So, again, why would imp fap lose its value?