Someone gave me a Vampire double barrel shotgun yesterday which though slow to load is quite effective.
Quad capacity is a very useful legendary effect on a double barrel shotgun. Having to load every 8 shots instead of every 2 makes the weapon a great deal more practical. If you're going to make heavy use of shotguns, the Enforcer perk in agility is worth considering. Stagger is a major advantage of shotguns. When I was using a rifle+shotgun build, I was able to get close to stunlocking most mobs most of the time with my shotgun. I preferred combat shotguns, but I did use a quad capacity double barrel as well.
I looked at the purveyors sale but unless I am missing something I did not know what I had bought until I had paid for it as there us only a generalised description.
Will be going back today to offload some legendary bits of armour I do not need.
You haven't missed anything. The purveyor is a gamble at enormous odds. You can only choose a random melee weapon, a random ranged weapon or a random piece of armour. The chance of getting what you want is infinitesimal. I've gambled away thousands of scrip, maybe as much as 10,000, and I don't recall getting anything I use from her despite the fact that I was only choosing ranged weapons. I might have got 1 or 2 weapons I use(d) that way, but I think I got all of them from Whitespring runs. But it's something to do with the hoard of useless legendaries you acquire and there is a chance of getting something useful.
Whitespring runs (golf club, chalets, maintainence building and its car park) are the best way to farm for legendaries, if you can do a Whitespring run easily and it's not too crowded. A run will usually get you a few legendaries and even 3* ones are not rare there. It's bugged, of course. Expect some of the ghouls to attack you while still in their sleeping position, which makes them very hard to hit outside of VATS. Expect some occasions in which every one of the couple of dozen ghouls in the golf club will rush out en masse to attack you in the car park before you even get to the door, with some still in their sleeping position. That bug managed to kill me this week.
I finally killed a scorchbeast queen tonight. Man, they take some killing. At least a dozen players turned up, geared up to the max. I used ~1500 rounds from my max level zealot explosive 50 cal machinegun. 106 damage per shot normally and it should have been 30% more as the scorchbeast queen should count as scorched. I did a small portion of the damage done. The difference was particularly striking when I switched to clearing some of the horde of other mobs that were swarming around. High level scorched everything, but even things like deathclaws took no more than a few seconds.
Annoyingly, it didn't count towards the "kill tough monsters" challenge. 12/13, only a scorchbeast queen left. Well, I killed one and it didn't count. I'm mainly playing for the few remaining challenges now, so that was annoying.
The reward from the quest and loot from the SBQ corpse yielded 1 plan I didn't already have - a prime capacitor for a laser weapon. Tiny woo.
I think I'm going to acquire a set of max level legendary unpowered armour, mod it as much as I can and see how it compares to power armour, just for something to do. Bethesda has greatly increased the rate at which fusion cores drain in PA again, so I'm using them faster than I can find them without a lot of server hopping. Probably a mistake - they did that before and fixed it with the next patch. SOP for Bethesda - most patches (re)introduce bugs.
EDIT: By the way, you can offload legendaries for scrip at any train station. There's a legendary "scrap for scrip" machine at every one. You don't need to go back to the train station the purveyor is at.