Neville had tried to purchase this thing multiple times even from foreign stores, but Pensieve was a very tightly regulated item and often needed approval from the ministry even in foreign countries.
Outside the ministry, only schools and some hospitals were allowed to ever own one. Imagine an artefact so powerful that it can allow looking through memories without the need of learning all that Occlumency and all the secrets of the victim will be revealed instantly.
Besides, Neville had thought making his parents watch the memories of their family and friends that can allow them to heal faster. This had to be purchased at any cost.
With a smile, Neville picked up a few other things whose names sounded funny or important or simply belonged to ancient categories. These were good for research for him and didn't cost much.
"Well, Mr. Burkes, the collections are fascinating, to say the least. Now, I think these are the things I want to purchase. Why don't you calculate the correct price for these items and we both can have a good start in the morning?"
Neville made his own small list and handed it over to Mr. Burkes. He knew one thing was famous for this man – buying cheap and selling at sky-high prices! But Neville wasn't against this policy as this is a basic feature for every businessman.
Then the haggling started. A man over 50 was haggling prices with a boy just 12 but both were stubborn in their own way.
"1500 galleons!" – demanded Mr. Burkes
"1500?! My-My…Why don't you just rob Gringotts Mr. Burkes? This is not even more than 700 Galleons." Neville replied with half the price.
"1400, Just because you are buying in bulk, I am offering a discount, Lord Neville!"
"750 – Just because that Pensieve is in working condition."
"Working condition? That is as best as they make. And this one is imported from France. The home of Alchemy association and greatest Alchemist Nicolas Flamel. Who knows, he might have even worked on this." Mr Burkes tried very hard to keep the prices at his acceptable range, but Neville became a goblin at this stage.
"800 – Take it or leave it! I am buying a single Vanishing Cabinet whose other pair is lost, a mask of unknown origin and the same can be said about a few other relics. The only thing good enough is this old Pensieve. So, I will say this finally – 800 Galleons and not a single knut more.
Mr. Burkes felt like his heart was bleeding with this low offer. He hated customers like these who haggle too much and don't have a fixed goal on which he can raise prices.
"Fine. Little Lord. You got yourself a deal!" Mr. Burkes after failing to intimidate Neville with his sketchy stare decided to just finish the transaction and collect the money that walked inside his store.
Besides, he knew the Pensieve is just stolen from a French school by their last caretaker, and he only paid 150 Galleons for this.
After half hour, carrying an expandable trunk for which Neville paid an extra 50 Galleons, the shopping inside the Knockturn Alley came to an end. Neville walked out of the shop with a smile while Mr Burkes also felt good after counting Galleons.
While passing through the Diagon Alley, Neville randomly checked the empty shops for the possible locations of the new library and found a perfectly suitable one at 92 Diagon Alley.
"Somehow, my fate is mixed with the twins it seems," Neville murmured to himself thinking that in future, 93 Diagon Alley will become famous as Weasleys' Wizard Wheezes and thought that the fate was funny sometimes.
After an enquiry, he noted down the address and found the real owners of this property were none other than McLaggen Family. He had already met them on his birthday and had a good impression of them.
Coming back to his manor, Neville first stored the trunk in his bedroom before placing a lot of safety charms and anti-theft charms on it. Inside his study, he wrote a very formal letter requesting the McLaggen family to sell their shop and explained his purpose clearly about the library. He knew being a political family, McLaggens won't miss such an opportunity to earn brownie points with the muggle wizards.
After all, there is a talk of new Muggle Protection law inside the ministry these days and his idea will receive a positive response from a major section of the wizarding world. While thinking about the Twins, he got inspired and wrote a letter to the Weasley twins about working together to create candies for kids.
He felt the healing potion if sold as a potion will not be able to generate a great income as its selling price cannot be too high than the actual cost price. After all, he would have to write all the ingredients of the potion. So, it was better to use that potion as the base and make colourful and creative candies.
Twins had a great imagination and with their ideas, he can create different flavours, and different kinds of additional features that will attract kids and other customers and this can be priced freely!
Sending his both owls away, Neville felt like the morning sun was like a big galleon shining in the sky.
"When did I become such a goblin?!" Speaking to himself at his foolish imagination, Neville went back to check on the girls. Unknown to him, his letter is creating a mini storm in the Weasley's house.